


Élan

by MangaFreak15



Series: SakuAtsu in love [5]
Category: Haikyuu!!
Genre: Alpha Sakusa Kiyoomi, Alpha Suna Rintarou, Alpha Ushijima Wakatoshi, Alpha/Beta/Omega Dynamics, Alternate Universe - Fantasy, Blood and Violence, Bottom Miya Atsumu, Breeding, Character Death, Explicit Sexual Content, Fluff and Humor, Knotting, Love at First Sight, M/M, Mating Bites, Mating Cycles/In Heat, Merfolk AU, Mpreg, Omega Miya Atsumu, Omega Miya Osamu, Sakusa's monster cock agenda, Stand Alone, Top Sakusa Kiyoomi, pls don't judge me for this, we love some feral alphas
Language: English
Status: Completed
Published: 2021-03-05
Updated: 2021-03-05
Packaged: 2021-03-17 04:36:30
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 19,592
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/29836128
Author URL: https://archiveofourown.org/users/MangaFreak15/pseuds/MangaFreak15
Summary: “…You still want me to fight for you?” Kiyoomi’s voice comes out hesitant.Atsumu tilts his head, confused. “Course I do, why wouldn’t I?”Kiyoomi huffs, burying one cheek against Atsumu’s striped scales. “Because I lost to that other guy today. He was more powerful than I expected,” he mutters, dejected. “He can provide for you, keep you safe, and give you strong heirs. Why would you still want me?”“…Because yer hot?” Atsumu can’t help but say.It's mating season again and Atsumu is reluctant to attend, right up until he sees a gorgeous Alpha named Kiyoomi and falls in love with him instantly.
Relationships: Akaashi Keiji/Bokuto Koutarou, Akagi Michinari/Ginjima Hitoshi, Hinata Shouyou/Kageyama Tobio, Kita Shinsuke/Ojiro Aran, Miya Atsumu & Miya Osamu, Miya Atsumu/Sakusa Kiyoomi, Miya Osamu/Suna Rintarou, one-sided Miya Atsumu/Ushijima Wakatoshi
Series: SakuAtsu in love [5]
Series URL: https://archiveofourown.org/series/2169279
Comments: 24
Kudos: 419





	Élan

**Author's Note:**

> Me @ my past self: 20k words in 1 week? Psh. Try 19k in 5 days.
> 
> I'm not sure how long I was expecting this to be, but it got kind of out of hand *side-eyes the word count*
> 
> Figures that my first ABO fic ever would be this monstrosity. Uhh, so, enjoy the fish porn? ┐(￣ヮ￣;)┌
> 
> Note: this is NOT underage! Merfolk majority age is 16, which = 18 in human years

The Great Inari Coral Reef Shoal is the single largest coral reef colony of tropical-based merfolk in the world. Situated in the south, teetering the fine line between the deep, dark waters of the Atlantic and the warm coastal waters off the coast of Australia, this massive coral reef stretches over 1000 miles long and covers an area that’s roughly the size of one million square miles. Day in and day out, it teems with hundreds of thousands of colorful fish and diverse aquatic species, from the smallest sea angels to the largest whale sharks. The lovely coral reefs shimmer the whole spectrum of colors, especially the areas that are closer to the surface and therefore shine beneath the diluted light of the waking sun.

It is here that a specific tribe of merfolk have made their home. Aptly named the Inari Reef tribe, they live amongst the reefs in harmony. Despite the reef’s enormous size, only a small part of it is actually inhabited by these merfolk. The tribe’s Alphas patrol around the reef daily in order to chase off intruders who intend to harm the coral reefs, namely humans who attempt to disrupt the delicate ecological systems.

The Inari Reef tribe is ruled by a skilled, powerful female Alpha named Tomoka, a lionfish mermaid as deadly as she is beautiful. And today, there is cause for celebration, for Tomoka’s two eldest sons have just turned sixteen, the merfolks’ age of majority. Starting from today, these two lionfish mermen will now be available to participate in the next annual spring mating gathering, where Alphas and Omegas from tribes all over the world come together to find a compatible mate and start their own families.

One of them is much less enthused about this prospect than the other.

Osamu ignores the loud, dramatic, whiny groan that Atsumu lets out for the umpteenth time as they swim in lazy circles around the giant whale bones halfway buried in the sandy ocean floor. “Why do we have to do this again?” Atsumu grumbles, twisting his torso to fit through a narrow gap in the open ribcage. “Can’t we just stay home?”

“Ya know why,” Osamu sighs, swatting at Atsumu’s striped tail as he torpedoes past his twin. “We just turned sixteen, which means we gotta make our official debut at the spring gatherin'. Face it, Tsumu, we’re old enough to mate now.”

“It’s fuckin’ stupid, that’s what this is,” Atsumu hisses, blowing bubbles into the water. He crosses his arms over his bare chest, his burgundy-tipped spines fluttering behind him in agitation. “Who’d wanna mate with lionfish like us, anyway? We’d sooner poison someone ta death.”

“We~ll,” Osamu drawls, drawing out the word with as much sarcasm as he can muster, “obviously our dear ol’ dad was successful considerin’ we were, y’know, _born.”_ He rolls over to escape his brother’s spines jabbing at him, snickering. Atsumu rolls his eyes at him. Osamu continues with a flippant wave of his hand, “‘Sides, ya know instinct’ll guide us.”

Instinct. Atsumu hates that word with every fiber of his being, because it implies that he has no free will to make his own choices. Especially considering that both he and Osamu are _male_ Omegas, which means they’ve got both male and female parts to make babies with. Atsumu despises the idea of some faceless Alpha breeding him like a bitch in heat, and being forced to pop out pups because of fucking _instinct._ Why couldn’t he have been born a proper Alpha instead of the weaker, submissive Omega? This sucks.

“I’m not goin’,” he insists stubbornly, a mulish set to his jaw.

“Ya hafta, moron. Else Mum’s gonna have yer head,” Osamu says. He swims away when he spots something shiny sticking out of the sand, intent on digging it out.

Atsumu clicks his tongue in annoyance. Damn his brother for bringing up their mom. The asshole knows that she’s the only one who Atsumu will obey, since she’s the leader of their tribe and an Alpha to boot. That doesn’t mean he’s happy about it, though.

Rather than argue back with something baseless, he opts to swipe the shiny trinket right out of Osamu’s hand as he holds it up to look at it. He cackles at his brother’s indignant screech and swims away as fast as he can, weaving in and out of the whale bones in an attempt to lose his twin.

“Give it back, ya asshole!” Osamu howls, cutting through the water with sharp flicks of his tail.

“Catch me if ya can!” Atsumu taunts, blowing him a raspberry. He ducks through the whale’s skull and quickly stuffs the item into a bed of kelp growing in the corner while he’s out of Osamu’s line of sight. Then he swims off, provoking his brother into chasing him all the way back to the reef. He’ll come back for the trinket later when Osamu’s not around.

It’s not that Atsumu doesn’t know how important his majority debut is—he knows far too well that he and Osamu will be held to higher standards than the other members of the tribe participating in mating season because they are Tomoka’s heirs, which means that either of them will be next in line to lead the Inari Reef tribe. Personally Atsumu doesn’t think he’s fit to rule; he hates rules, hates restrictions, and loves the freedom to do whatever the hell he wants. Osamu can be just as wild as him sometimes, but he’s generally the more level-headed twin, more calm, more prone to making rational decisions than impulse-driven Atsumu. Hell, even his _name_ ‘Osamu’ means ‘to rule’. It’s perfect!

But Atsumu is still one of Tomoka’s eldest sons, so he has a duty to uphold certain obligations to the clan, as much as he doesn’t want to. Unfortunately, that includes announcing his availability to mate at the upcoming spring gathering. Atsumu really doesn’t want to have to find a mate so early in his life and live out the rest of his days birthing endless litters of guppies for whatever Alpha ends up claiming his venomous ass. He looks at their tribe’s mated Omegas (who are, incidentally, mostly women), watches their pups scream and cry and wail and generally make a nuisance of themselves, and can’t help but shudder at the thought of becoming one of them. Who would want to deal with _that?_ Not Atsumu, that’s for sure. He honestly just doesn’t feel like he and Osamu are ready for it yet. Or rather, that _he_ isn’t ready yet. Osamu doesn’t seem bothered by this whole thing at all.

When they return to the coral cave that the tribe lives in, Osamu fuming behind him because he has no idea what Atsumu did with the trinket he had found, Atsumu can’t help but glance at the resident Alphas who are lounging around in the main communal room, flexing their muscles to the titters of the younger merfolk. To his horror, he finds his eyes straying back to them as he passes by, watching the lean curves of their impressive biceps and the way their pectorals shift with every movement. He makes a disgusted face when one of them notices him staring and winks. He speeds up to get out of their sight as fast as he can, cheeks flushing faintly pink in embarrassment. Ugh, what’s so great about them, anyways?

Atsumu adamantly denies thinking that he’d wanted to be one of them not too long ago.

Osamu doesn’t miss his blush and smirks at him, poking his cheek with one finger. “Oh, what’s this? Ya finally noticin’ how attractive our tribe’s Alphas are?” he mocks, his eyes twinkling with false sympathy.

“Shaddup!” Atsumu snarls, shoving his twin brother away.

Osamu just laughs at him, “Loser.”

Atsumu sticks his nose into the air spitefully and swims away.

Later that night, after the tribe has eaten dinner and various members are preparing to settle down to sleep, Atsumu remembers about the shiny object he had stolen from Osamu earlier. After checking to make sure nobody’s following him, he sneaks out and goes back to the whale bone graveyard. He swims into the skull and digs around in the patch of kelp to grab the item. He holds the item up and squints at it. His night vision isn’t the best, but it’s good enough to pick out a few relevant details about the trinket.

It’s a necklace; little yellow and pale green shells strung on a thin silver chain, a lone black and white spiral shell sitting right in the center. Atsumu loves it instantly and doesn’t hesitate to put it around his neck. The center shell falls right below the gap between his clavicles, settling nicely against his skin. He strokes a finger over the smooth surface, feeling an odd sense of calm wash over him. It feels… just right, having this necklace on him.

When he swims back to the coral cave, Osamu catches sight of him and shrieks, “So ya _did_ hide it somewhere, ya thief!”

“Finders keepers,” Atsumu gloats, twirling in place, the necklace flowing in the water with him. “Doesn’t it look great on me?”

Osamu punches him on the shoulder, grumbling, “I found it first, asshole.” He pauses in the corridor, eyeing his twin up and down contemptuously. “An’ it makes ya look like a seahorse. The ugly kind.”

“Oh, shut yer trap, yer just jealous that it looks better on me than ya,” Atsumu retaliates, swimming deeper into the cave.

“I never wanted that awful thing anyway!” Osamu yells at his back, his voice bouncing off the walls of the coral reef. Atsumu snorts to himself as he continues on. What a liar.

Not long after, the two mermen are accosted by their five excitable younger siblings. Of the seven of them, only Atsumu and Osamu are pure lionfish. Three of their siblings are lionfish-wrasse hybrids, the other two lionfish-barracuda because Tomoka had been mated a total of three times before she had decided that seven children were enough and she no longer needed a mate. At the tender young age of five, Atsumu and Osamu had unfortunately borne witness to what Tomoka did with her last partner, a barracuda Omega from the north. Needless to say, not a single word about the incident has passed through either of their lips to this day.

Atsumu lifts one arm so that their youngest sister can wriggle her way underneath and press against his warm side. “Shouldn’tcha all be in bed by now?” he asks, amused. He and Osamu carefully pull their spines back so that the venomous tips don’t hurt any of their siblings.

She peers up at him with bright golden eyes, grinning toothily as she chirps, “We were waitin’ fer ya, Tsumu-nii! An’ fer ya too, Samu-nii! ‘Cause we wanna sleep wi’chu!”

“Yeah!” the others chorus, clustering around them.

Atsumu huffs, but deep down he secretly enjoys having his younger siblings cling to him and look up to him as a role model. He looks over at Osamu and smirks when he realizes that he’s got three attached to him while Osamu only has two. ‘I win,’ he mouths smugly. Osamu rolls his eyes and swats him with his tailfin.

* * *

After a long winter where the denizens of the Great Inari Coral Reef were forced to hunt more actively in order to keep the little ones alive in colder-than-average temperatures, spring finally arrives. And with the coming of spring and the promise of warmer waters, there are only a handful of days left before the eligible members of the tribe have to make the journey to the mating grounds. Those days are spent grooming themselves obsessively, getting rid of old, dull scales to allow newer, more vibrant ones to come in. In order to entice a suitable mate, all merfolk have a distinct ‘mating display’ that hits its peak during mating season. The display varies between species, but it ranges all the way down the color spectrum from the brightest crimson to the darkest ebony.

Even Atsumu and Osamu, despite being near-identical twins, have different patterns for their mating displays. Atsumu’s tail glitters with overlapping stripes of brilliant red, white, and purple scales, the same pattern appearing on his arms, shoulders, cheeks, and around his ribs. Osamu’s stripes are more on the neutral side, with maroon, ivory, and the occasional band of black shining in the muted light. Atsumu’s dark hair lightens to a soft, yellowish hue, while Osamu’s turns silvery-gray. Everyone in the tribe oohs and aahs over their colors, some joking that now it’s easier to tell them apart.

“At least nobody will mistake ya fer each other at the matin’ grounds,” jokes their whale shark friend Aran.

On the day that the tribe is to set out for the site of the gathering, Atsumu wakes up with a curious warmth in the pit of his belly. It’s his first time experiencing it, but oddly enough, it doesn’t bother him at all. He pokes dubiously at his flat stomach, wondering if he’s got any eggs starting to grow inside of him yet. He still hates the idea of being used solely for breeding, but maybe having his own guppies swimming around won’t be _too_ bad as long as he can snag a good mate. The idea of having to watch Alphas posture all day and try to one-up each other in order to score a mate is definitely a turn-off though.

An unmated Omega will enter the pre-heat stage in the days leading up to mating season, but their heat won’t be officially triggered until they receive a bonding bite from an Alpha in rut, and an Alpha can only go into rut when a pre-heat Omega scent marks them. This evolutionary cycle came into existence in order to prevent any unwanted accidents from happening in the off-season, as well as between members of the same tribe. Mated Omegas have a chance to trigger a bi-yearly heat cycle to increase the chances of a successful pregnancy, since at least forty percent of all mer pups tend to die before their first birthday, whether by inability to acclimatize to the environment, incompatibility between the genes of the two parents resulting in unsuccessful mutations, or by predation from natural ocean hunters.

Before he heads out to join the rest of the departing tribe members, Atsumu stops by a certain room deep in the coral cave’s inner sanctum, where his senior Omega mentor Shinsuke is resting. Shinsuke is a very beautiful striped beakfish merman with dual-toned hair that is mostly silver with black tips, and his tail shimmers with silver, white, and dark-gray scales. When he’s in peak condition, Shinsuke is what many of the members of the Inari Reef tribe consider to be an ideal Omega.

Right now though, Shinsuke is very pregnant. Atsumu can see just how distended his belly is all the way from the entrance of the room. The beakfish merman spots him from where he’s laying down on his bed of kelp, caressing his stomach.

“Ah, Atsumu. Are ya leavin’ now?” he asks, struggling to sit up despite how huge he is.

“Whoa, ya don’t hafta do that! Aran’ll kill me if it looks like I’m botherin’ ya!” Atsumu says, waving his hands frantically to stop the other Omega from moving. Shinsuke laughs, but sinks back down on to his bed. Atsumu feels bad that both he and Osamu probably won’t be around to help with the birth because they’ll be busy at the mating grounds. After Aran, who is Shinsuke’s mate, they are the ones who are probably the closest to him. Atsumu stares at the older Omega for a moment, his eyes lingering on Shinsuke’s belly. “Does it hurt?” he finally asks. “Matin’, I mean.”

Shinsuke looks at him calmly. “No. Not if ya find the right one fer ya, at least.” He strokes his stomach. “Are ya afraid because it’s yer first time and ya don’t know what ta expect?”

“Yeah,” Atsumu admits. It’s always been easy for Shinsuke to see right through him.

“It’s okay ta be nervous, but ya’ve really got nothin’ ta be afraid of,” says the beakfish, slitted brown eyes giving him an intense stare. “I know ya aren’t keen on it, but promise me that ya’ll at least _try_ ta give someone a chance. Once ya do, ya’ll see that it ain’t really as scary as ya’ve made it out ta be.”

Atsumu gnaws on his lower lip with a frown. “I can’t promise that, Shin-san,” he murmurs, crossing his arms over his chest. “But… I’ll do my best, I guess.”

Shinsuke nods, a faint smile lighting his face up. “That’s all I ask of ya.”

At that moment, Aran enters the sanctum, clutching a fat fish in one hand. “Oh, Atsumu! Good luck out there, my friend!” he says cheerfully, clapping a giant hand on the lionfish merman’s shoulder. “I’m sure ya’ll find someone willin’ ta put up with yer bratty attitude!”

“Aran!” Atsumu squawks indignantly. “That’s rude!” Shinsuke chuckles in the background as he accepts the fish and begins to chew on it.

“Try not ta offend anyone while yer there,” he chortles. Atsumu turns red and protests that he’ll do no such thing and how he definitely knows better than that.

Despite the couple’s teasing, Atsumu does feel less anxious about the whole thing after talking with them, which he suspects had been Shinsuke’s goal the moment he saw Atsumu swim in. He goes outside to join his tribe with a smile on his face.

Osamu sidles up next to him, giving him a suspicious glance. “What’re ya smilin’ ‘bout? It’s creepy,” he remarks.

“Ya know we have the same face, idiot. Yer just callin’ yerself creepy,” Atsumu retorts without any heat.

“Oh, fuck off, ya know what I meant.”

Tomoka clears her throat, silencing the idle chatter between the members of the tribe. Atsumu and Osamu break away from the crowd to swim up to her. As they approach, they bow their heads to her, acknowledging her position as the head of the tribe. She nods back, granting them permission to be beside her as she gives her usual yearly speech. Atsumu takes his spot on her right, Osamu on her left. The twins are a bit of an anomaly insofar as Omegas are concerned, considering that they both have strong, supple bodies on par with or better than many Alphas. This is made all the more apparent by how much they dwarf their own mother in size, the fierce lionfish mermaid more than a head shorter than both of them. But Tomoka is still the tribe’s leader, and she has a presence that demands attention. Her steely gaze sweeps over the crowd, then she starts to speak, her powerful Alpha’s voice ringing loudly through the space.

“Everybody here? Alright, then listen up, ‘cause I’m only gonna say this once! Today, we will be travelin’ towards the Fukurodani Basin up in the northwestern region. It will take us roughly two days to reach it. Some of ya have made this journey before, but most of ya haven’t. Do not, and I mean, _do not_ stray from the pod while we are enroute to the matin’ grounds. If ya wander off, ya _will_ be left behind, an’ ya can be eaten by the sharks fer all I care. Understand?” There’s a rousing round of confirmations from the tribe. “Great! The only other thing I would like to say is this: when we arrive at the site, if ya commit any actions that will bring dishonor upon our tribe, ya will be swiftly exiled and will no longer be welcome in our territory. And yes—” she cuts her gaze sideways to slide over the twins, “—that goes fer both of ya, as well. I expect nothin’ less than the best behavior from my kin. Got it?”

“Yes, ma’am,” says Atsumu and Osamu in unison, along with the rest of the crowd.

“Good.” Tomoka makes one last sweep over the tribe before she turns around and begins to swim away. “Now, follow me! We’ve got a long way ta go.”

* * *

The Fukurodani Basin is an enormous, rocky crater deep in the Atlantic Ocean, smack dab right on the equator. It’s about 3000 feet deep and five miles across, bioluminescent green algae crawling all along the sides and revealing thousands of holes in the walls that are big enough to comfortably house two merfolk at a time. The bottom of the crater is lined with fields of kelp weaving to and fro, with a central circular platform of solid rock rising up in the center. The Fukurodani Basin is maintained by the Fukuro Basin tribe, whose elderly leader recently stepped down and appointed a new tribe leader in his stead, a powerful Alpha kitefin shark named Koutarou, along with his mate of three years, an Omega spinner shark merman named Keiji. This year will be the first year that Koutarou and Keiji will be the ones to host the spring gathering.

Atsumu gapes as the basin comes into view after two long days of traveling from their coral reef home. There are already several tribes there, the basin teeming with all sorts of merfolk. There are so many different colors and shapes and sizes that Atsumu doesn’t even know where to begin. A quick glance over to Osamu shows that his twin is equally lost at the dizzying sight. It’s their first time being so far away from their home reef, so it’s not too surprising that they both have a lot to take in. Despite his initial reluctance to come, Atsumu finds himself actually excited to go exploring in this new place.

Tomoka swims forward fearlessly, having witnessed this sight too many times to be awed by it anymore. After a moment, her tribe follows her into the madness.

They pause right at the lip of the basin. Tomoka turns around, her long brown hair drifting in waves around her deceptively-delicate shoulders. She throws out a hand, her spines fanning out behind her, and says, “Welcome to the Fukurodani Basin. I’m sure yer all tired and hungry from the long trip, so go find somethin’ ta eat and a cubby to nap in. Make sure ya choose wisely though; the cubby ya claim will be yers fer the duration of the season. Got it?” She makes sure everyone confirms before she dismisses them and swims off to nab a spot for herself.

The tribe scatters. The twins are about to head off when their friend Michinari, a cardinalfish Omega, calls out to them, “Atsumu! Osamu! Wanna go find cubbies together?” Michinari’s long, thin black fins flow through the water as he waves at them.

Atsumu is hungry, and he’ll bet that Osamu is too, but they both agree that it will be in their best interests to scope out their own spot before finding something to eat. That way they won’t have to choose from the leftovers later on, even though they aren’t the last ones to arrive and there are still plenty of holes to choose from.

“Yeah, let’s go,” he agrees. “Race ya!” He darts off with a laugh.

“That’s cheatin’, Tsumu!” Osamu and Michinari dive after him, catching up to the other merman in no time.

They swim around together, poking their heads in and out of various spots while respectfully avoiding the ones that have already been marked. Atsumu dismisses most of them as too small, too shallow, or too weirdly-shaped. He and Osamu need enough space to stretch out the venomous spines on their backs, so the cubbies have to be perfect. Michinari has a little more leeway with his choices because he’s smaller than the twins and his fins are little more than ribbons, so he can easily curl up in any decent space. But he wants one that will also be able to house a good-sized mate, as he intends to snag one.

Surprisingly Osamu is the first to find a spot. It’s a fairly open space near the bottom of the crater, with a wide entrance and a curved ceiling that perfectly accommodates his spines. Osamu turns over and starts to rub his scent glands over the dips and curves of the rock walls, sticking his tongue out at Atsumu and Michinari. Atsumu returns the gesture and swims away in a huff, Michinari trailing after him while giggling.

The dark-haired cardinalfish finds his next, not too far away from Osamu, but a little higher up on the wall. He waves gleefully at Atsumu from his curled up position inside. Lucky bastard.

Ugh, why is he the last one to find a good spot?

Atsumu grumbles as he makes his way back up another section of the wall, peering through the available cubbies. That one’s too narrow, that one’s too cramped, that one’s taken already, that one’s not smooth enough, that one looks hard to fit into…

It takes another fifteen tries before Atsumu darts into an opening that’s close to the top of the dropoff, pausing to gauge the spot thoughtfully. It’s comfortably deep, and wide enough for him to stretch out his spines without brushing the edges of the cubby. Even accounting for a potential mate who could be bigger than him, there’s still plenty of room leftover. He tests the floor with his fingertips. While there’s a few traces of sand carried there by the underwater currents, the rock feels polished and secure, with a subtle depression in the center that feels wonderful against his scales when he curls up in it. He sighs as he lays his cheek against the cool stone, feeling so content that he nearly dozes off.

“Oi, get up, sleepyhead. We’re gonna get food now,” Osamu says from the entrance, Michinari fluttering around behind him. He glances around the cubby that Atsumu has claimed for himself. “Nice digs. But mine’s better.”

“Ya wish yers was better’n mine.” Atsumu’s stomach growls, reminding him that he hasn’t eaten in nearly half a day. He sits up with a yawn. “A’right, ‘m comin’. I feel like I could eat a whale right now.”

“Ya don’t need no whale meat, yer ass is already fat enough as it is,” Osamu mocks. Atsumu rolls his eyes at him, swatting at him with his tailfin.

“C’mon, Atsumu! I think I saw some bluefin tuna swimmin’ around earlier, yer favorite!” Michinari chirps, which catches Atsumu’s attention right away. There’s bluefin tuna in this area? Oh _hell_ yeah, that’s what he’s talking about! Atsumu spares a few moments to cover the cubby in his scent before he follows the other two Omegas back outside.

They race to the top of the basin, weaving in and out of each other’s paths. Michinari was right; there’s tuna here. Atsumu wastes no time chasing after his favorite fish, intent on gobbling down his fill. Osamu and Michinari aren’t as picky about their choices, both of them just snagging whatever crosses their paths and devouring them. Despite the lack of coral reefs, there’s a surprising abundance of marine life in this area. That’s probably a big reason why the Fukurodani Basin is set as the merfolks’ mating grounds, ensuring that nobody goes hungry and that there’s ample opportunities for Alphas to prove that they can provide.

Once Atsumu has eaten enough to make him feel mildly bloated, he starts to swim back to his cubby, intent on taking his nap. He stops in his tracks when a large shadow falls over him, and he looks up to see who it is.

His jaw drops as a stunningly beautiful merman swims in front of him, clearly an Alpha by the faint pre-rut pheromones that he’s giving off. His thick, powerful tail propels him through the water as easily as breathing, his sleek, muscular form cutting a striking figure against the backdrop of bioluminescent algae. He’s got a head full of silky black curls, his skin so pale that it’s nearly translucent enough to see the blue veins underneath. His tail is sheer black, with small patches of white all the way down to his tailfin, complemented by the curved dorsal fin directly over his spine. He’s gorgeous. Atsumu _wants_ him. He thinks back to Shinsuke’s words about giving someone a chance, and finds that once again, his senior Omega is absolutely correct. Atsumu starts to think that maybe this whole mating thing won’t be so bad after all, with an Alpha that fine swimming around.

He tries to nudge his brother without taking his eyes off of the merman as he circles overhead aimlessly, whispering, “Who’s _that?”_

When Osamu fails to respond, Atsumu frowns and jabs him harder. Osamu still doesn’t reply, and surprisingly, neither does Michinari. When Atsumu turns his head to yell at them, he sees why.

Apparently they’re both in the same boat as him. Osamu is still holding a half-eaten fish in his hands as he watches a handsome merman with an eel-like tail swim about not too far away from them, his poison-green eyes narrowed in concentration on the shoal of fish that he’s currently hunting. Michinari is staring curiously at a different merman with a head of sandy-blond hair, who is laying on his belly in the sand with his fins flattened, eyes tracking a single slow-moving squid as it comes closer to him. The moment the squid comes into range, the merman lunges up, catching it between his powerful jaws with ease. Then he swims away, keeping low to the ocean floor.

Atsumu almost feels embarrassed for them seeing that vacant, moony-eyed stare directed at other merfolk. Is that what _he_ had looked like when he had been admiring the orca merman earlier? Disgusting.

His solution is to slap his dumb brother in the face with a sharp flick of his tail. Osamu screeches so loudly at the unexpected assault that they catch the attention of multiple merfolk nearby, including the eel merman that Osamu had been eyeing up just now. Atsumu cackles as the merman changes course from chasing fish to actually start swimming towards them, which makes Osamu’s eyes bug out in panic and he drops the fish he was eating.

“Tsumu, ya fuckin’ asshole! Stop laughin’!” he hisses, attempting to shove his brother down into the sand. He looks torn between wanting to strangle Atsumu and wanting to watch the Alpha approach with long, sinuous strokes of his tail.

“Oh, did that one catch yer eye, Osamu?” Michinari looks far too delighted by this, even though he had been in the same situation not ten seconds earlier. “He’s cute. Ya’ve got good taste.”

“Not ya too!” Osamu groans. Atsumu grins and highfives the other Omega.

The eel merman comes to a halt in front of them, his narrow green eyes looking back and forth between the three of them. Atsumu unsubtly pushes Osamu forward, which earns him a yelp and a nasty glare from his twin that promises vengeance for this humiliation later.

The Alpha clears his throat. “Hello there,” he says. His voice has a hint of a drawl behind it, but is otherwise smooth. “It’s pretty rare to see identical twins here. Where are you from?”

“What, not gonna introduce yerself first?” Atsumu mocks. The eel merman flicks a disdainful look at him. Osamu shoves him off to the side, his striped spines waving in warning. “Hey!”

“Ignore him, he’s got no manners,” Osamu says to the merman so smoothly that Atsumu wonders if he somehow fell into a different dimension in the span of two seconds. Michinari turns away so that nobody can see him giggling into his fist, even though his shoulders are shaking. Osamu continues, “I’m Osamu from the Inari Reef tribe down south. This dumbass here is my twin brother Atsumu, and that’s our friend Michinari.”

“Who’s the dumbfuck who was panickin’ earlier—” Atsumu starts to say, but Osamu glares at him and slaps his tailfin over his mouth to shut him up so that Atsumu doesn’t embarrass him anymore in front of the Alpha that he likes.

The eel merman laughs. “Wow, you guys are entertaining. I’m Rintarou from the Eastern Coastal Reef tribe. It’s nice to meet you and your friend, Osamu. I wish I could say the same of your brother,” he chortles.

Atsumu gapes at him as Osamu and Michinari both burst out laughing. “I can’t believe—I am _so_ offended right now,” he huffs, turning his nose up and swimming away irately with hard strokes of his tail. Osamu definitely found his perfect match; that eel’s just as obnoxious as his twin and they’re going to be even worse together. Well, screw them! Rintarou isn’t as good-looking as the orca merman that Atsumu has his eye on, anyway.

As he returns to his cubby to take his long-overdue nap, he glances around to see if he can spot the orca. He swallows his disappointment when the merman is nowhere in sight. Oh well, he’ll have more chances to court his chosen Alpha once mating season actually kicks off. He curls up in the little dip in the center of his spot and falls into an exhausted sleep, rubbing the black and white shell on his necklace for good luck.

* * *

It takes another day and a half for the rest of the participating tribes to arrive at the mating grounds. In that time, Atsumu had only seen the orca Alpha once, while he’d seen Osamu and Rintarou practically joined at the hip and, on two occasions, he’d seen Michinari chatting up the angelshark merman that he’d been watching before. Atsumu’s own choice had proven to be quite the elusive one, and notoriously difficult to track even though Atsumu has the scent of his pre-rut pheromones memorized. The one time that he does finally catch a glimpse of the Alpha, the merman doesn’t even look in his direction despite Atsumu’s best attempts. Atsumu knows he’s got a flashy mating display, so either the orca is not interested or he’s playing hard to get because mating season hasn’t started yet. Atsumu chooses to go with the latter option.

After all of the tribes are well-rested, the spring gathering officially kicks off. They all gather on the circular platform at the bottom of the crater. The leader of the Fukuro Basin tribe is already there, his muscular arms crossed over his impressively-ripped torso. His quieter, but equally intense mate floats beside him, his mating mark on full display to show that he’s taken so that nobody mistakes him as a participant in the event.

They introduce themselves first as the hosts of this year’s mating season. “Welcome to the Fukurodani Basin, my fellow merfolk! I am Koutarou, the new head of the Fukuro Basin tribe, and this is my lovely mate, Keiji!” Koutarou booms, projecting his voice so loudly that it rings through the enormous basin like a clap of thunder. “Before we get this party started, we would like to have the leaders of each tribe come up and introduce themselves and their tribe, along with any heirs they have participating this year! One at a time, now!” They swim off to the side to make space for the first tribe leader to come up.

Tomoka takes this as her cue to make the first introduction. Atsumu and Osamu obediently accompany her to the center of the platform, placing themselves on each side of her as they did before the journey here. Tomoka already has a commanding presence despite being smaller than her sons, and she captures the crowd’s attention easily.

“Good mornin’, my friends. As many of ya already know, my name is Tomoka, the leader of the Inari Reef tribe that resides in the south. This year’s gatherin’ is special ta me, because this year my beloved sons, my pride and joy, are debutin’ for the first time today. This is Atsumu—” Atsumu bows his head, “—and Osamu—” Osamu does the same, “—both of whom reached the age of majority last autumn. They are lionfish mermen and both are Omegas, so I expect nothin’ but the best Alphas for them. That’s all, thank ya fer havin’ us.” Atsumu and Osamu both do a slow twirl, fluttering their fins and their spines to show off their coloration and make them more appealing to the crowd.

Atsumu’s eye catches on someone who holds himself slightly apart from the crowd and he grins mentally when he realizes that the unknown orca merman is watching him, dark eyes boring into him with heavy intent. He throws in a little hip shake, feeling a sense of satisfaction rise up within him as the orca shifts in place, the heat in his gaze dialing up a notch. _Keep yer eyes on me,_ he thinks gleefully. Then his moment in the spotlight is over and he exits the stage along with his brother and mother.

A few other tribe leaders do their introductions along with their heirs. Atsumu notes which ones have the most potential as desirable mates if he doesn’t manage to win over the orca Alpha—such as Wakatoshi from the Deep Ocean tribe or Tobio of the Caribbean Reef tribe. Then he realizes that the orca is slowly making his way up to the center of the platform along with another, older orca merman who must be his sire. Oh, excellent. The orca merman that he has his eyes on is another tribe’s heir, which places his standing above both Osamu’s and Michinari’s choices. No wonder he gives off a bit of that ‘royalty’ feeling; his form and demeanor just oozes aloof majesticness.

The older orca clears his throat. He speaks with a calm, level voice without much inflection, “Hello. I am Katsutora, the leader of the Pacific Nomads tribe. My youngest son is finally making his debut this year. This is Kiyoomi, he is an orca merman like I am and he is an Alpha. I look forward to seeing who he decides to match with today.”

_Kiyoomi._ Atsumu mouths the name to himself, delighted as it rolls off of his tongue easily. Awesome, he finally has a name to put to that gorgeous face.

Kiyoomi does a brief loop in the water, showing off his sleek form and impressive dorsal fin. He locks eyes with Atsumu and adds a shimmy of his hips at the end, drawing his hands slowly down the lean lines of his well-toned body to accentuate how sculpted he is. Atsumu has to admit that the subtle flex definitely works on him. The small pit of warmth in his belly grows larger as he watches the Alpha dance for him. There’s really no need for him to do that though; Atsumu already has eyes only for him.

Once all of the tribes have been introduced, Koutarou and Keiji once again take the center stage. This time, Keiji is the one who announces the first event to kick off the season, “We will be starting this year off with a hunting game. The rules of the game are simple: Alphas must prove their ability to provide by catching whichever fish they think is the preferred meal of the Omega that they intend to court. This also doubles as a game of prediction, so Omegas are not allowed to give the answer away, although they can give out clues to favored suitors. Omegas can have multiple suitors, but for the sake of this round, there will be a strict no-killing rule implemented. To keep things interesting, Alphas are allowed to steal each other’s catches, so guard yourself wisely. If an Alpha presents an Omega with a fish and the Omega accepts, that Alpha will get priority points going into the next round. But if an Alpha presents an Omega with a fish and the Omega rejects it, the Alpha will not receive any points and will have a lower chance of scoring a mate in the next round. I feel that this is not something that I should be saying as it _should_ be common sense, but I’ll say it for the sake of posterity: under _no_ circumstances is an Alpha allowed to kill an Omega, nor is an Omega allowed to kill another Omega. Should you commit this taboo, you not only bring dishonor to yourself, your family, and your tribe, but you voluntarily forfeit your life upon completing the act. Is that clear to everyone?” He waits for the confirmation, then continues, “Good. Now if I could have all of the Omegas move to this side…”

Atsumu smiles prettily over the heads of the other merfolk as Kiyoomi gives him a hard stare, his brows faintly knitted in the middle, presumably in an attempt to figure out what kind of fish Atsumu prefers. Atsumu will probably accept anything that Kiyoomi offers him, but if the orca merman brings back a bluefin tuna, that will be a huge bonus. He decides that he’s not going to give out any clues. He loves a good challenge and, if he’s being honest, the Omega part of him wants to see how well the Alpha will fare without any direction whatsoever. He grins back at Kiyoomi, flaring his striped fins and spines in a signal for good luck. He also holds up the center shell on his necklace and kisses it, peeking seductively over the top of it towards the orca. Kiyoomi licks his lips in response, the heat in his gaze darkening the irises from mellow gray to a smoldering black.

“Go forth and be victorious, my fellow Alphas!” Koutarou bellows enthusiastically, whipping both hands up and bringing them down in an X-shape in front of him. “The hunt starts… _now!”_

A cloud of churning bubbles and sand erupts around them as all of the Alphas swim up and out of the crater in a frenzy. Atsumu watches Kiyoomi glide away with strong, powerful strokes of his tail, a smile on his lips.

_May the best suitor win._

* * *

It doesn’t take long for the first wave of Alphas to return. Among them is a sleek, dark-haired reef shark merman who Atsumu recognizes as Tobio of the Caribbean Reef tribe. He watches him for a moment, to see where Tobio is heading, and is partly relieved when he realizes that the shark merman isn’t going in his direction. Instead, Tobio jets down to the bottom of the crater faster than everyone else and offers a perfect blue mackerel to a tiny, excited, orange-haired clownfish Omega with white stripes. The Omega squeaks happily as he accepts the fish and eats it right in front of the Alpha, who looks on with a satisfied grin. How cute.

Atsumu is approached by a few Alphas, but none of them are carrying bluefin tuna, so he is more than happy to reject them all. Osamu gets slightly less suitors due to his more muted coloring, but nonetheless, he doesn’t accept any of the offerings either. They are both waiting for a specific merman.

A shadow falls over Atsumu and he turns to the left to spot a very large merman approaching him. A very large and extremely handsome merman, who is holding a beautifully fat bluefin tuna between two meaty hands. He looks stoic, his brows thick over two intense, almond-shaped eyes. From the wide gray dorsal fin jutting out of his spine and the dark gray and white markings around his neck and shoulders, he’s a great white shark, one of the most powerful breeds of merfolk in the world, second only to killer whales. Atsumu recognizes him as the heir of the Deep Ocean tribe, Wakatoshi. The shark offers him the tuna without a word.

Atsumu looks down at the tasty treat, feeling himself salivate at the thought of digging into its sweet, fatty flesh. This merman isn’t Kiyoomi, but Keiji _had_ said that Omegas are allowed to have more than one suitor. Atsumu eyes the shark merman, running his eyes appreciatively over the mer’s bulky muscles and sleek gray tail with a white underbelly. He could do worse, he supposes.

He takes the tuna, the first offering that he accepts. But he doesn’t bite into it just yet. He looks at the merman and says boldly, “Yer Wakatoshi, ain’tcha? I’ll accept yer gift, but ta be frank, ya ain’t the one that I’m waitin’ fer.”

Wakatoshi doesn’t even blink at the declaration, maintaining his aloof facade with ease. “That’s not an issue. I am confident that I will emerge victorious,” he says, full of self-assurance. He inclines his head. “Enjoy your meal.” And swims away to wait for the first round to end, joining the other Alphas who also had their offerings accepted.

Well then. Don’t mind if he does. Atsumu happily gobbles down the tuna while he scans the open waters for any signs of his primary suitor. To his right, Rintarou finally shows up with his offering for Osamu. Or rather, offering _s._ Atsumu knows that his brother doesn’t have a favorite, he eats pretty much anything, so Rintarou made an excellent guess. Osamu lights up with a huge grin upon being handed five different types of fish, wasting no time on chowing down on each one. Rintarou watches him eat with a pleased smile, his poison-green eyes softening as he gazes dopily down at Atsumu’s brother.

Disgusting, but well, good for them.

Michinari’s favored suitor also returns before Kiyoomi. The sandy-haired angelshark gruffly thrusts an Atlantic salmon into Michinari’s hands. The cardinalfish merman beams at him, making the angelshark look away with an embarrassed blush, and promptly devours his gift. Atsumu sighs mournfully as he realizes that he is, once again, last. Last to find a cubby, last one to get an offering from his preferred suitor.

The blond lionfish is starting to get impatient when he finally spies Kiyoomi leisurely making his way back into the basin, dragging an enormous bluefin tuna behind him. It’s nearly twice the size of the one Wakatoshi had given to him. In fact, the fish is so huge that even other Alphas are looking taken aback by the size of the offering.

Atsumu grins madly, his eyes shining with gratitude and awe. Here is an Alpha who won’t back down from a challenge, which is exactly the kind of mindset he wants from a mate.

Kiyoomi looks at him with those deep, dark, fathomless eyes. Like Wakatoshi, he also doesn’t say anything to precede his offering, merely drops the giant tuna carcass in front of him with the expectation that Atsumu will eat it. But unlike with Wakatoshi, there’s no dithering about whether he should accept it or not. Atsumu wastes no time eating it down to the bones right then and there, watching the orca merman’s lips curl up into something resembling a smile. Atsumu hadn’t noticed before, but Kiyoomi has two little black dots over one of his eyebrows, which makes him look extra-handsome in Atsumu’s eyes.

“Thanks fer the meal,” Atsumu says, stuffed to the brim with delicious tuna. He could use a nap right now, but unfortunately he can’t while the hunting event is ongoing. He chooses to swim around in slow circles to speed up his digestion without making himself nauseous.

“You’re welcome.” Kiyoomi looks very pleased with himself for making the correct choice.

Atsumu jerks his head in Wakatoshi’s direction, who is studying Kiyoomi’s profile intently, sizing up his competition. “Think ya can beat that guy fer the right ta mate me?”

“Obviously,” Kiyoomi replies, returning Wakatoshi’s stare with his own challenging expression. “Orcas are superior to great white sharks.” The two Alphas enter a staring contest, both unwilling to back down. Their pride as apex predators is on the line here. The first to blink loses.

Unfortunately their contest is interrupted when the tiny clownfish Omega from earlier stumbles between them with a squeal, giggling loudly as another small Omega, a yellow butterflyfish mermaid, chases him merrily. They appear to be podmates, if their casual familiarity with each other is anything to go by. They’re so engrossed in whatever game they’re playing that they don’t seem to notice the tension between the two Alphas at all.

“Well,” Atsumu cuts in, bringing both Alphas’ attention back to him, “I’m only gonna mate with one o’ ya, whoever’s stronger between ya. I ain’t settlin’ fer second best, just so ya know.” He smirks when the fire of challenge lights up in both mermen’s eyes. That ought to make sure both of his suitors bring their all into this competition. He wants them at their best.

When the two Alphas swim away, Osamu and Michinari slide up next to him with matching mischievous grins. “Well, well, look atcha, goin’ after the top two tribe heirs now. And here I thought ya were deadset on not findin’ a mate. Y’know, I still recall ya tellin’ me that this whole thing was stupid,” Osamu says smugly. Atsumu wants to punch that dumb smirk off his face.

Michinari chimes in, “What a lucky bastard ya are, Atsumu! Gettin’ two apex predator types fightin’ over ya. What’s yer secret, man?”

Atsumu puffs his chest out haughtily, “They just know quality when they see it, I guess.”

“Pfft,” Osamu snorts. “Never mind, this was a bad idea. Yer head’s gonna be so big by the time we get home that ya won’t fit into the cave anymore.”

“Rude!” Atsumu complains, shoving his twin. “Just fer that, I’m gonna make damn sure that my kids’re stronger than yers!”

Osamu gets a very strange look on his face as Atsumu blurts out his latest declaration. He stares at Atsumu as if he’s been replaced by an alien lifeform. Michinari makes a confused noise and Atsumu turns to him with a frown. “What? What’d I say?”

“Atsumu—” Michinari says, his thin eyebrows ticking upwards in surprise, “—yer already thinkin’ of havin’ kids?”

Oh. _Oh,_ that’s what the issue is. Atsumu feels his entire body flush when he registers why Osamu and Michinari are looking at him so oddly. Growing up, Atsumu had been the most outspoken of them about not wanting his own guppies, despite how cute he thought their younger siblings were. And prior to this year’s mating season, Atsumu had been adamant about how much he hated the idea of being used for breeding. Now, he’s apparently considering the idea and finding it more appealing than he initially thought, and all it took was being courted by two powerful Alphas.

He crosses his arms defensively as he stammers, “S-so what if I am?! We’re probably all gonna be pregnant by the end of this whole thing anyway!”

“Uh, nope, Rin an’ I will probably wait ta have kids,” Osamu says, shaking his head.

“Same fer me,” Michinari adds with a small smile. “We just turned sixteen, no need ta settle down so early, right?”

Atsumu’s belly throbs hotly, his mind conjuring up images of what it will feel like to have an Alpha (more specifically, Kiyoomi or Wakatoshi) on top of him, biting him, breeding him, thick, hot cocks pistoning into his cunt and knotting him as they come. And wow, that’s… that’s fuckin’ hot. A flash of Shinsuke’s knowing smile passes through his mind, along with the words _“it’s okay ta be nervous, but ya’ve really got nothin’ ta be afraid of”_ echoing through his head. Shit. Okay. Maybe Atsumu is into this whole mating thing after all.

“Yer seriously thinkin’ ‘bout it?” Osamu asks in disbelief. Atsumu’s pre-heat scent swells between them, the amount of pheromones he’s giving off nearly doubling in that short amount of time, saturating the water with a sweet smell.

“Leave me alone!” Atsumu wails, burying his face into his hands. _“Yes,_ okay? I’m… I can’t stop thinkin’ ‘bout it, Samu! I didn’t think this was somethin’ that I’d actually want, but, but—!”

Osamu and Michinari exchange uncertain glances over his head. Osamu pats his brother on the head, a small measure of comfort against the backdrop of all the new emotions and feelings that Atsumu is suddenly experiencing. “Well, it’s not a bad thing, I guess,” says the silver-haired twin awkwardly. “If ya want it, then go fer it, Tsumu.”

“Yeah,” says Michinari. “Don’tcha always do what ya want, anyway?”

Okay, this is very true. Atsumu peeks through his fingers and mumbles, “Ya ain’t gonna make fun o’ me or nothin’?”

“Oh, we will,” Osamu promises, putting his brother into a headlock and grinding his knuckles down in Atsumu’s light-yellow hair, earning him a yelp. “But that’s never stopped ya from givin’ back as good as ya got.”

Atsumu huffs even as he throws his brother off, his spines flexing dangerously. “Thanks fer the vote of confidence. But really, ya guys ain’t feelin’ the heat at all?” He puts a hand on his belly.

Michinari shrugs. “I feel it an’ it’s there, but like, I don’t feel the urge ta do anythin’ ‘bout it. My time will come, y’know? No rush.”

“What he said,” Osamu adds with a shrug. Atsumu scowls, poking at his stomach. Why is he the only one that's feeling like this?

The hunting game wraps up shortly. Koutarou gets their attention by loudly clapping his hands and yelling, “The hunt is _over!_ Amazing job today, everyone! I can see a lot of happy Omegas from here!” The crowd chuckles at his energy. “But don’t worry, mating season isn’t over yet! Now we’ve got the second event of the day to get through: a treasure hunt! But not just any treasure hunt, this one will be a little bit different from past years!”

Keiji takes this as his cue to explain the rules, “In the past, the treasure hunt consisted of Omegas hiding a personal item and the Alphas being tasked with finding and bringing it back. This part won’t change, but it will be slightly different in how it’s executed. We are going to have each Omega perform a dance in front of the Alphas and whichever Alphas want to court that Omega will become one group. Once all the groups have been formed, the Omegas will then go and hide their items. When they return, the Alphas who were favored in the previous round will have a one-minute head start to find the item of the Omega they intend to court. You are allowed to steal the item from each other as long as you are stealing from someone in the same group, but if you steal a different Omega’s item, you will be disqualified from the game. Again, there will be no killing in this round. Does everyone understand?” The crowd unanimously agrees.

Atsumu notices his brother frowning and leans closer. “What’s wrong?” he asks.

“I don’t have any personal items,” Osamu mutters back. “Ya think they’ll let me go find a rock or somethin’ before we start?”

“Well, they hafta. No point in havin’ a game like this if the Omegas don’t got anythin’ ta hide, right?”

Osamu eyeballs his necklace. “I _would_ have had somethin’ if ya hadn’t stolen that from me,” he sniffs.

“Too fuckin’ bad, it’s mine now.” Atsumu grins sharply, fingering the spiral shell resting below the divot of his collarbones.

“I don’t have anythin’ either,” Michinari hums. “They’ll probably have a short period of time fer us ta find something ta hide. Won’t be much of a treasure hunt, otherwise.”

“That’s what I _said.”_

Before the argument could go on, Keiji starts to speak again, “I’m aware that not everyone has a personal item on them presently. Therefore, we will allow ten minutes for Omegas without an item to go and find one and return here to begin the dances. If you already have an item that you wish to use in the treasure hunt, please make sure that the item has been saturated in your scent. With that said, Omegas, you may now search for the item that you wish to use.” Keiji swims back to his mate’s side, and Koutarou greets him with an utterly besotted grin.

“Let’s go, Michinari,” Osamu says, tugging on the cardinalfish’s arm. “Tsumu, ya stay here. I don’t trust ya not ta try ta steal somethin’ I find again.”

“Anythin’ ya find out here wouldn’t be as awesome as my necklace anyway,” Atsumu brags. He takes the spiral shell and gently rubs it against the scent glands on his neck, making sure that the necklace is completely covered in his pheromones. Osamu rolls his eyes at the display and drags their friend away.

His brother ends up finding an odd, heart-shaped rock while Michinari digs up an old human coin out of the sand. Atsumu still thinks the necklace is way better than those dinky little things. He radiates smugness from his entire body as Osamu gives him dirty glances.

After ten minutes are up, the dances begin.

During Atsumu’s turn, he specifically seeks out Kiyoomi, and by extension, Wakatoshi. They are on opposite sides of the crowd of Alphas, so Atsumu chooses to focus on Kiyoomi. He makes eye contact with the orca merman and slowly, very slowly, raises his arms up, flaring his colorful fins. He twists to the side, showing off his array of venomous spines, then he spins in place, shaking his hips. He draws his hand up the length of his bare belly, up his pectorals, and cups his face with one hand as he spins in the opposite direction, his other hand twisting seductively above his head. Then he puts both hands on his tail, where his humanoid torso meets scales, and drags his fingers across his slit teasingly. He smirks when Kiyoomi looks back at him with hunger, his eyes like two black holes in his face. He twirls again, sweeping from side to side, his hands tracing through the water lovingly. Then he ends his dance by flaring his fins and spines outward, blowing a kiss in Kiyoomi’s direction. The orca looks ready to devour him. Excellent, that’s exactly the reaction that Atsumu is looking for.

Wakatoshi is certainly affected, too. He tries to keep up the stoic face, but there’s a pink tint to his cheeks, and his eyes are equally dark with lust. When Keiji calls for Atsumu’s suitors to gather, he’s actually kind of surprised by how many Alphas are in his group.

_Heh, take that, Samu,_ he thinks smugly, sending an infuriating grin in his twin’s direction. Osamu shakes his head with a sigh as he takes the stage after Atsumu. His brother’s dance is very similar to Atsumu’s, but more… delicate? Maybe that’s not the right word, but watching him move, there’s a certain sense of serene grace to his every movement that Atsumu knows he wouldn’t be able to mimic in a million years. And that’s fine, he’s got a good chunk of Alpha suitors in his corner, although he’s only got eyes for two of them. Meanwhile Osamu won’t care how many he gets as long as his dance is good enough to enthrall Rintarou.

And enthrall him, he does. Atsumu and Michinari are practically holding their sides, shaking with laughter, at the absolutely gobsmacked, slack-jawed expression on Rintarou’s face when Osamu basically shakes his hips in his face. Then when it’s Michinari’s turn, Atsumu and Osamu howl with glee from the sidelines when Michinari ends up getting flustered halfway through his dance because of how intense Hitoshi’s stare is and ends up floundering his way through the second half.

Once the Omega dances are over and the Alphas have been sorted into groups, it’s time for the Omegas to hide their objects. To prevent the Alphas from cheating, they are all sent out of the basin with Koutarou, who will wait for a signal from Keiji to lead them back in.

Atsumu takes off the necklace and looks around for the perfect place to hide it. Kiyoomi can use echolocation to find it, but Wakatoshi probably has a better sense of smell, so it will be easier to sniff it out. But the basin is humongous; it stretches further than the eye can see. He should definitely hide it far away from the center platform to make it more challenging for his numerous suitors.

Amidst the fields of kelp that cover the bottom of the rocky basin, Atsumu ends up finding a tiny little opening beneath a big rock that he slips the necklace into, making sure that the necklace is neatly tucked away. He rearranges the kelp to conveniently cover the opening and spreads the sand around evenly so that his hiding spot looks exactly like every other part of the kelp fields. He hangs back, satisfied when he can’t tell that there’s anything different, then he returns to the platform.

_Ya better win this one, Kiyoomi,_ he thinks as he rejoins his brother. Michinari emerges from the kelp fields not too long after, devoid of the old coin.

Once all of the Omegas have returned, Keiji looks up towards the top of the crater and makes an odd clicking-trilling noise. Then Koutarou returns with the Alphas in tow, a big grin on his handsome face. Atsumu waves at Kiyoomi when he spots the merman amongst the crowd. The orca returns the gesture, determination painting his features in the form of a furrowed brow and lips pressed tightly together.

“Alright, let’s get this party started!” Koutarou bellows. “Are you ready, my fellow Alphas? Then let the treasure hunt… _begin!”_ He throws his arms out wide, and the Alphas jet off.

Osamu sidles closer to his brother, his eyes tracking Rintarou as he disappears into the field of kelp. “Who d’ya want ta win out o’ yer two biggest suitors?” he asks. “I’m guessin’ the orca ‘cause ya’ve been watchin’ him the most this whole time.”

Atsumu’s own eyes linger on the flash of black and white as Kiyoomi swims away. “Yeah,” he admits. As he expected, Wakatoshi is the first one to head in the direction where he had hidden his necklace, but Kiyoomi isn’t too far off the mark either. “Wakatoshi ain’t bad lookin’ either, but Kiyoomi just feels like _the one,_ y’know?”

Michinari pretends to wipe a stray tear from his eye. “Aw, lil ‘Tsumu’s all grown up an’ makin’ _decisions_ fer himself now. I feel like a proud mama.”

“Shaddup, Michi!” Atsumu barks, turning red. Osamu chokes with laughter at his side, slapping his tail with his hands.

They wait together on the platform, watching the Alphas fight amongst each other for their chosen Omega’s trinket. While there is no killing allowed in this round, that doesn’t mean that maiming is out of the game. And when Alphas get desperate, they get downright _mean._

The Omegas who had only a few suitors get their items returned first, including Michinari. He grins happily when the sandy-haired angelshark deposits the old coin into his hands, only looking mildly scratched up compared to a few others that they’ve seen nursing deep gouges and bite marks. Hitoshi even smiles back, although it’s little more than a slight upturn of his lips.

The spectacle that is Tobio almost crash-landing on the platform after fighting off a feisty goblin shark merman is enough to turn heads. Atsumu’s eyebrows shoot up when he realizes how banged up the reef shark looks. He’s bleeding from multiple bite marks over his arms and his tail, as well as a set of shallow scratches cutting across one eye. His dorsal fin looks like something had tried to take a chunk out of it and failed. But still, he swims back to his chosen Omega and presents a colorful beaded bracelet to him, his eyes dark with the satisfaction of coming out victorious.

Atsumu shivers, glancing back to the kelp fields anxiously. He’d forgotten how violent Alphas can get, perhaps because this is his first time participating in mating season and only now is the true extent of an Alpha’s aggressive nature finally making itself known. The water has taken on a slightly pink tinge in response to all the blood being shed over simple trinkets. He wonders if he’s going to see Kiyoomi like that, especially when going up against an equally ferocious merman such as Wakatoshi.

His belly throbs again just imagining it, his inner Omega strangely thrilled by the thought of being worthy enough to fight over.

When Rintarou finally returns, he’s not nearly as badly off as Tobio, but he does have his fair share of battle wounds. He holds up Osamu’s heart-shaped rock with a tired smile, his teeth coated in red. Osamu accepts it, leaning forward to press a little kiss against the eel’s forehead. Rintarou brightens instantly.

_Gross,_ Atsumu scoffs.

While Michinari and Osamu are busy soothing their favored suitor’s wounds, Atsumu swims towards the edge of the platform. His eyes keep scanning the area in hopes of catching a glimpse of either Kiyoomi or Wakatoshi. He knows he has other suitors, too, but when they’re up against a killer whale and a great white shark, he doesn’t think that they stand a chance.

The other Alphas trickle in one by one, each bearing marks of battle as they present the trinkets to their chosen Omegas. Atsumu gets more and more antsy the longer that time passes by without any sign of his suitors. In fact, it’s shaping up to look like he’ll be the last one to receive his trinket.

He briefly wonders if maybe they just haven’t found his item yet, but it’s not like he made it _that_ hard to track down.

Then, as if summoned by his thoughts, Wakatoshi appears. Atsumu’s eyes widen and a small gasp escapes him. The shark looks like he’s definitely been through the ringer. His fins are in disarray, a few of the smaller ones tattered and trailing useless behind him. There are deep gouges and bite marks all over him, shredded bits of skin peeling from the wounds on his torso. His dorsal fin looks like someone tried to rip it off. He’s clutching Atsumu’s necklace tightly in one bloody fist.

But what hits Atsumu the hardest… is that there is no sign of Kiyoomi.

As Wakatoshi approaches, his arm outstretched to drop the necklace into Atsumu’s waiting palms, Atsumu can only think with bitter disappointment that his absence means that Kiyoomi… _lost._

Wakatoshi shakes the necklace to remove any traces of blood from it, then gives it to him. “I won this time,” he rasps, blinking slowly, “and I am confident that I will come out on top tomorrow, as well.”

Atsumu puts the necklace back on. “Well, yer doin’ a great job provin’ it so far,” he says, rubbing the black and white spiral shell. “Ya should get yer wounds treated before they get infected.”

Wakatoshi nods at him, then swims away to take care of his injuries.

Koutarou announces that the treasure hunt is now over, and that everyone should rest up for tomorrow’s big battle. Osamu and Michinari give Atsumu pitying looks, which he waves off because he doesn’t want their sympathy. It does worry him that Kiyoomi still hasn’t shown up despite the event being over, and he says as much to them.

"Go find yer loverboy, then," Osamu says, pushing Atsumu off the platform. The blond lionfish screeches as he tumbles head over tail into the kelp field below. He can hear Michinari burst out laughing all the way down.

Those bastards, Atsumu seethes, righting himself so that he doesn't break his spines. He swims away, heading out in the direction that Wakatoshi had come from. Sniffing lightly, he catches a faint whiff of Kiyoomi's pre-rut pheromones tinged with the sharp iron tang of blood, indicating that the merman is, at the very least, moderately injured. Given the nature of the injuries on Wakatoshi, Atsumu expects that the orca is probably just as banged up, or worse.

He swims faster.

Thanks to the lack of sunlight on the ocean floor, the Fukurodani Basin is only lit by the bioluminescent algae crawling on its walls and the occasional glowing rock. Atsumu has decent night vision, but even he nearly misses the black of Kiyoomi's tail amongst a particularly dark area of kelp. He does a double take when he realizes that it's Kiyoomi's dorsal fin he's seeing rather than another string of seaweed and he hastens over to the orca.

The Alpha is so still that for a moment, Atsumu fears that he's actually dead, despite the no-killing rule. But when he pauses, hovering uncertainly over the merman, he hears quiet, labored breathing rattling the strands of kelp. Okay, not dead, just wounded.

Kiyoomi's tailfin twitches. Then he slowly rises out of the kelp, blinking tired, pitch-black eyes at Atsumu. "Oh, it's you," he murmurs, flopping back down with a groan. "Come to mock the loser, then?"

"What would I do that fer?" Atsumu says, settling besides the other merman. His eyes adjust to the lack of light and he winces internally when he sees all of Kiyoomi’s injuries. They’ve mostly stopped bleeding, a few of the deeper bite marks sluggishly oozing into the water. He reaches out, tentatively poking at the back of Kiyoomi’s head.

The orca growls at him, then immediately looks contrite. “I’m just checkin’ fer head injuries,” Atsumu assures him, moving his fingertips through dark curls. Kiyoomi’s hair is very smooth; just a mop of bouncing rings that wave gently in the water. Atsumu prods at various spots around the merman’s skull, and feels content when he doesn’t find anything. He starts to let go, but Kiyoomi’s hand shoots up and grabs his wrist.

“Feels good. Keep going,” the orca says sleepily. He shuffles around in the sand until his head is resting directly on Atsumu’s lap. Atsumu blushes at the close contact, but resumes stroking Kiyoomi’s head.

They remain like this for some time, Kiyoomi falling into a light doze. Atsumu absently strokes the orca’s wounds with his other hand, snatching his hand back at each snarl and hiss. But Kiyoomi doesn’t try to bite him, so he resumes tending to the Alpha’s injuries the best he can.

“Hey, Kiyoomi,” he whispers, lightly poking the orca in the cheek. Kiyoomi grumbles and opens one eye.

“What?”

“Erm, this might sound weird,” Atsumu begins, squirming in place, “but can I… lick yer wounds?”

Kiyoomi gives him a single long, slow blink. “Excuse me?” he says, his brows drawing up in disgust.

“It’s not a fetish or anythin’!” Atsumu blurts out frantically. “But uh, apparently Omegan saliva contains minor healin’ properties or some shit like that, so—I wanna make sure yer in a good shape fer tomorrow!”

“…You still want me to fight for you?” Kiyoomi’s voice comes out hesitant.

Atsumu tilts his head, confused. “Course I do, why wouldn’t I?”

Kiyoomi huffs, burying one cheek against Atsumu’s striped scales. “Because I lost to that other guy today. He was more powerful than I expected,” he mutters, dejected. “He can provide for you, keep you safe, and give you strong heirs. Why would you still want me?”

“…Because yer hot?” Atsumu can’t help but say.

He guffaws loudly when Kiyoomi turns a completely bewildered expression on to him, his eyes wide with surprise. “Well, that’s not the only reason, but that is one of them! I think yer really beautiful, more so than Wakatoshi,” he admits, resuming running his fingers through Kiyoomi’s hair. “An’ sure, Wakatoshi’s got it all, too, but _yer_ the one that I want. I liked ya from the moment I saw ya. It ain’t over till it’s over, right? Ya mighta lost this one, but yer not gonna give up and lose tomorrow, are ya?”

Kiyoomi grabs his hand and presses it to his cheek, sighing softly. “No, I suppose I won’t. I can’t let myself be seen being pathetic enough to lose to a great white shark.” He smiles, and it takes Atsumu’s breath away. The way his entire face softens, the corners of his lips pushing his pale cheeks up the slightest bit, his eyes slightly crinkled with happiness. He is so, so gorgeous and Atsumu just _wants_ him. Not Wakatoshi. Not anyone else vying for his hand. Just him; just Kiyoomi.

It takes a moment to remember what he had originally wanted out of this conversation. “So,” he hedges, “will ya let me lick yer injuries?”

“That sounds disgusting,” Kiyoomi says with a grimace. “But if it’ll help me, then… go for it, I guess.” He sits up, letting go of Atsumu’s hand, and shifts back so that he and Atsumu are facing each other.

Atsumu catalogues the wounds from the worst to the least threatening. The tear in Kiyoomi’s dorsal fin and a huge bite mark that took a chunk out of his shoulder look the worst. Kiyoomi isn’t wrong about this being disgusting, but Atsumu has licked his fair share of wounds over his sixteen years of life. The healing factor in Omegan saliva also comes with antibacterial properties, which will prevent the injuries from getting infected. Kiyoomi will have some grisly scars after this, but if he manages to be victorious over Wakatoshi, it will be undeniable proof that he _earned_ the win instead of it being handed to him on a silver platter.

Atsumu leans forward, smirking when Kiyoomi’s pupils dilate at the proximity. His eyes were already dark before, but now they’re like two black holes in his face, swallowing up what little light they have left to see by.

“Tell me if yer uncomfortable with this,” the lionfish says, deciding to deal with the shoulder bite first. He closes his mouth to let saliva pool inside, then he lets a glob of it fall on the injury. Kiyoomi hisses upon contact and tries to jerk away, but Atsumu holds him steady, his tongue coming out and helpfully spreading the saliva around the raw edges of the bite. Kiyoomi whines and growls the whole time as Atsumu cleans his injury up. A couple of times, Atsumu swears he sees Kiyoomi’s eyes flash scarlet, a sign that he’s struggling to keep his Alpha side in check.

Atsumu has a higher degree of immunity to ocean-born bacteria thanks to his body’s ability to secret toxins for his venomous spines, so he’s completely unaffected as he cleans one wound after another. Kiyoomi has the worst reactions to the shoulder bite and the tear in his dorsal fin, but he quiets down at last when Atsumu moves on to the smaller lacerations across his torso and his arms.

When he’s done, he sits back to let Kiyoomi regain his senses. “Ya feelin’ better now?” he asks, plucking out a strand of kelp to chew on so he can get the taste of blood out of his mouth.

The Alpha runs his hands over his injuries, making a surprised sound when he realizes that most of them feel like they’re already at least a week old. There’s a slight twinge from his shoulder and his dorsal fin, but there’s little to no pain accompanying them. He experimentally flexes the muscles of his arms and is elated to find that he can move them with no problem.

Atsumu grins. Omegan saliva may not be a one-shot cure-all, but it’s no joke when it comes to speeding up merfolks’ natural healing. “I’ll take that as a ‘yes,’” he says, getting up. “I better go back now, but first, I wantcha ta tell me: are ya gonna win fer me tomorrow?”

Kiyoomi’s dark eyes bore into his, a savage smile splitting his face in two. “I’ll stop for nothing less,” he promises, grabbing one of Atsumu’s hands and kissing his knuckles. “I will make you mine, Atsumu.”

Atsumu believes him.

* * *

The second day dawns bright and early, with the Alphas providing a huge feast for the Omegas. Atsumu eagerly snatches up one of the bluefin tuna and a few of the smaller fish for breakfast. Osamu and Michinari circle around him, leaping and diving for their own share of fish. They squabble over a particularly large blue mackerel, which ends up as a three-on-one when Tobio swoops in and snatches it from right under their noses.

Atsumu spots Kiyoomi through the shoal of quick-moving fish and he makes a beeline for the orca. Kiyoomi sees him coming and stops to greet him.

“Mornin’, Omi!” Atsumu says brightly.

Kiyoomi frowns in confusion, mouthing, “‘Omi’?”

“Yeah! It’s a nickname fer ya, ‘cause y’know, Kiyoomi is kinda a mouthful an’ I like given’ nicknames to mers that I like!” Atsumu babbles. “Like my brother, he’s Samu! An’ my friend o’er there, that’s Michi! So since I like ya an’ I want ya ta win, yer gonna be Omi! Whaddya think? D’ya like it?”

For a long moment, Kiyoomi just stares at him. Atsumu doesn’t let his grin falter despite the anxiety slowly ticking up in his head. Aw crap, does he hate it? _Please don’t hate me,_ Atsumu prays.

Then Kiyoomi’s face softens with a small smile. “I’ve never had a nickname before,” he says quietly, pleased as punch. “I love it, thank you.”

Atsumu’s heart stumbles in his chest and he feels giddier than a guppy on their first outside excursion. “Yer welcome!”

Kiyoomi reaches out, taking the spiral shell of Atsumu’s necklace in one hand. He presses his lips to the smooth surface, making Atsumu’s heart skip another beat. “Thanks for coming to cheer me up yesterday. I won’t falter today. I’ll make sure I win, for you,” he says, raising his dark, dark eyes to Atsumu’s face. He drops the shell so that he can cradle Atsumu’s face instead, smiling beatifically. “Wait for me?”

Atsumu nods quickly, putting one hand over Kiyoomi’s. “I’ll wait fer ya as long as it takes,” he promises. He turns his face so that he can lightly kiss the palm of Kiyoomi’s hand. “I’ll wait fer ya, so make sure ya come back ta me, Omi.”

“I will.” Kiyoomi drops his hand and swims away, an expression of deep concentration taking over his face.

When Atsumu returns to the spot where his brother and Michinari are waiting, he’s greeted with one disgusted expression and one excited grin. “What?” he snaps defensively.

“Yer gross,” Osamu deadpans, as if he hadn’t been doing the exact same thing with Rintarou yesterday.

“I don’t wanna hear that from ya!” Atsumu says indignantly.

Michinari laughs. “Think yer man will win today?”

“He promised that he would,” Atsumu answers.

Osamu looks like he’s about to say something, but then he closes his mouth and nods towards something behind Atsumu. When Atsumu turns around, he spots Wakatoshi swimming towards him, parting the sea of merfolk with his powerful figure. The injuries from his fight with Kiyoomi yesterday still look fairly nasty, but they’ve mostly scabbed over. He pauses in front of them.

“Atsumu. I will be victorious today,” he declares, his stoic countenance never wavering.

Atsumu hums, subtly flaring his fins out. “Sorry, buddy, but Omi has promised me that he’ll win today. So do your worst.” He gives Wakatoshi a smile that’s as sharp around the edges as he can make it without setting off Wakatoshi’s inner Alpha.

Wakatoshi’s brows pinch together just the slightest bit, seemingly off-put by Atsumu’s headstrong personality. But he simply nods and leaves.

Osamu elbows him in the side, making him double over, wheezing. “What the hell, Tsumu, yer an Omega, ya can’t just go around challengin’ an Alpha!” he hisses into Atsumu’s ear.

“I _wasn’t,”_ Atsumu protests, righting himself. “I just want Omi ta beat ‘im at his best!”

Osamu is about to argue back when a voice interrupts them, “Atsumu! Osamu!”

The twins automatically turn and bow their heads as Tomoka swims towards them. Michinari also bows, but he moves further away from them since he wasn’t addressed by their tribe leader.

Tomoka looks between both of her sons with a proud smile on her face. “I’m happy ta see that both of ya are being courted by strong Alphas, especially _you,_ Atsumu. Who knew that my brash Omega son would have two clan heirs fightin’ o’er him at his very first matin’ season?” she laughs, shaking her spines with mirth. She then fixes him with an intense stare that makes him fidget in place. “I understand that yer favored suitor lost yesterday’s round, though. Whoever wins today, Atsumu, I expect ya ta accept them. No matter who it is. Got it?”

“Yes, ma’am.” Atsumu fully expects Kiyoomi to come out on top, so this isn’t really an issue. He squashes the tiny, fearful part of him that wonders if Kiyoomi will actually be alright going up against the great white shark a second time.

“And Osamu—” Atsumu’s brother snaps to attention instantly, “—I can’t say I’m particularly fond o’ eels, but I suppose ya’ll stick with yer choice anyway.” Osamu nods solemnly. Tomoka claps her hands together. “Great! Today is gonna be a big day fer us. The second day event is always a free-for-all battle between suitors, so it _will_ get nasty. This event is when the Alphas will truly release themselves and fight ta the death. Don’t grieve if yer favored suitor loses or dies. That just means that they weren’t strong enough ta deserve ya, anyways. Understand?”

“Yes, ma’am.” Satisfied, Tomoka moves towards Michinari to speak with him.

“Mum’s pretty scary when she wants ta be, huh,” Atsumu whispers, watching her go.

Osamu whacks him on the back of the head, earning him a short screech from his brother. “Yer just noticin’ that _now?_ Moron,” he says, rolling his eyes.

“Well, _excuse_ me,” Atsumu huffs, getting his revenge by smacking Osamu with his tailfin. They tussle for a few minutes, snapping and snarling at each other without any real heat.

The twins stop playfighting when Koutarou yells for everyone to gather up. This time, all of the tribe leaders are there, floating in the water beside the Fukurodani Basin hosts. Seeing them all gathered together makes for an intimidating presence. Tomoka is by far the smallest of the leaders, as well as one of the only female Alphas in attendance, but no one would dare suggest that she’s weak with the confident aura that she gives off. She’s the head of the Inari Reef tribe, the largest tropical merfolk colony in the world; there’s no room for weakness there.

When he has everyone’s attention, Koutarou starts to speak, “Good morning! I hope you all had enough time to rest up yesterday, because now we’ll be going straight into the main event! Who’s excited?!” He grins when the Alphas bellow in agreement, the sound of their roars swelling and echoing off of the walls of the crater. “That’s the spirit! So here’s how it’s going to work: we’re going to have a battle royale between Alphas! This platform is big enough to hold four battles at a time, and each fight will be overseen by one of the tribe leaders. Tribe leaders can’t oversee battles involving merfolk from their own tribes, just to make sure things stay fair. Everyone with me so far?”

“Yeah!” comes the thunderous shout.

“I love all your energy, folks!” Koutarou laughs, clapping his hands together. He sweeps the crowd with his bright golden eyes. “Now, I do want to say that while fighting to the death _is_ allowed today, my partner and I would _prefer_ it if you could use nonlethal means to subdue your opponents! We’re all kinsmen at the end of the day, remember that. So, who wants to go first?”

Atsumu can see Kiyoomi and Wakatoshi trading glares in the crowd, the tension between them sizzling as hot as volcanic vents. The fight for his hand is going to be a messy one, he just knows it. So he decides to wait for other fights to happen first, because chances are, the battle between the two heirs will be the one that everyone wants to watch play out in real time.

His belly throbs again, and though Atsumu knows it’s just pre-heat hormones winding him up in anticipation for a true heat, he’s hard-pressed not to just stick his own fingers into his slit and get himself off to relieve the ache that’s been slowly growing within him. Despite this being his very first mating season and his first time experiencing pre-heat, some part of him just _knows_ that his fingers won’t be enough. He needs an Alpha’s cock inside of him, filling him full of cum and knotting him so that none of it can leak out. Atsumu quietly whines to himself, shifting in place. Osamu and Michinari send him concerned glances, but they all know that there’s nothing any of them can do right now.

Fuckin’ instinct. Atsumu has never been so grateful for it, or hated it more.

The first four battles are for Michinari, the clownfish Omega (Atsumu thinks his name is Shouyou), his butterflyfish podmate Hitoka, and some other Omega from an Arctic tribe that Atsumu has no interest in.

Of those four battles, the most vicious one is the one over Shouyou. Once again, the last two fighters are Tobio and the goblin shark Alpha, Kourai. A battle between two sharks is bound to end in bloodshed and death. Tobio has the size advantage and a more lethal, tearing bite, but Kourai is sturdy and has a stronger bite force because his back teeth are made to crush bones easily. They snap at each other, tailfins slapping the water wildly, ripping into each other with everything that they’ve got. Atsumu shudders as the water is saturated with the smell of violence, blood, and hostile Alpha pheromones. Shouyou is practically weeping against Hitoka, his hands flung up over his face as if to keep himself from watching, but unable to stop looking at them between his fingers.

In the end, Tobio wins by lunging at Kourai and clamping his jaws shut around the other Alpha’s throat, bringing him down to the ground with a wail. He has enough remaining sense not to bite all the way down, but the threat of having his throat torn out makes the goblin shark go still, reluctantly conceding defeat to his opponent.

Tobio pulls off from the other Alpha and roars, the cry of a hardwon victory reverberating through the arena. Hitoka pushes her podmate forward to accept his suitor so they can cement the mating elsewhere. Shouyou squeaks fearfully as Tobio's blood-red eyes turn upon him. The Alpha jets towards him, grabbing him by the waist, and then they're off to where Atsumu presumes is Shouyou's cubby. Yeah, that little Omega will definitely be pregnant in a few days.

Michinari's suitor Hitoshi wins without much fuss, and the two go cavorting off together arm in arm like old friends. They aren't in nearly as much of a rush as Tobio and Shouyou were, and it shows.

Osamu's turn comes in the next round of battles, along with three nameless Omegas who are very small and dainty in comparison to Osamu's bulk. Rintarou has to fight his share of competition, but he's more than capable of fending them off. His eel-like tail is slippery and willowy, giving him an unprecedented flexibility that frustrates his opponents because they have such a difficult time hitting him at all. Atsumu makes a face at the hunger in his twin's eyes as he watches Rintarou's every move with a borderline obsession.

"Who's gross now," he mutters, elbowing Osamu in the ribs.

"Fuck off," Osamu murmurs back, halfheartedly returning the jab. "Yer still the most disgustin' o' the two of us."

"I can see ya moonin' an' it's really ugly."

"Ya know we've got the same face, which means ya just admitted that yer ugly." Osamu punctuates his statement with a smirk.

"Ya didn't deny bein' ugly just now," Atsumu points out with an identical smirk.

Osamu shrugs. "I'm pretty enough for Rin."

"Nasty." Atsumu pretends to gag.

"Look who's talkin', Mr. I've-got-two-heirs-fightin'-o'er-me."

"Better than no heirs at all."

The roar of the crowd draws their attention back to the arena, where Rin literally pile-drives the last of his competition into the rocky ground, snapping the other Alpha’s neck with no remorse. The cold bloodlust in his eyes shines through the scarlet tinge, but the crimson of his irises quickly reverts back to poison-green when he looks up and meets Osamu’s elated gaze. He tosses the corpse aside and makes a beeline for Atsumu’s twin. Atsumu wisely hangs back to avoid interrupting them.

Osamu meets him halfway, colliding with one another like they haven’t seen each other in forever, and then Rintarou is coiling his tail around Osamu and whisking him away, out of Atsumu’s sight. Thank Neptune, Atsumu does _not_ want to see his brother sucking face with an Alpha any time soon.

The tribe leader responsible for the dead Alpha takes the body away before the battle royale resumes. Once the second round is over and Koutarou comes forward to call for the next set of combatants, Atsumu raises his hand. From the corner of his eye, he can see Kiyoomi and Wakatoshi tense and posture aggressively at each other. The hostility is rolling off both of them so thickly that it actually deters all the rest of Atsumu’s would-be suitors from entering the arena with them, which is probably a good thing because he doesn’t believe for a second that the two Alphas would have enough sense remaining in them to hold off on killing the others as they attempt to maim each other to death. There’s less collateral damage this way.

Along with Atsumu’s suitors, the battle over a rather apathetic-looking Omega with two-toned hair also commences, and the set of four is neatly rounded off by two smaller battles over more nameless Omegas. But Atsumu isn’t interested in them. He is solely focused on his two suitors.

As if sensing the unusually potent killing intent between Kiyoomi and Wakatoshi, Koutarou offers to personally oversee their battle. Keiji understandably stays behind him the whole time, only minute twitches of his facial muscles indicating his discomfort at being in such close proximity with two antagonistic, unmated Alphas that are exuding sheer animosity from their pores.

Atsumu breathes in the smell of violence, like lightning-sharp ozone in the water mixed with the coppery tang of faded blood. Kiyoomi’s pre-rut scent is stronger than ever, a combination of volcanic sulfur and salty sea grapes with a hint of something sour, and Atsumu really shouldn’t find that smell as intoxicating as it is, but well, here he is. Wakatoshi’s own pre-rut scent rises in the water around them, an earthy, salty musk that is actually not that pleasant to Atsumu’s nose when he’s bombarded with it. Well, if he didn’t have a reason to choose between them before, now he definitely does.

The moment that Koutarou gives the go signal, the two Alphas are charging towards each other, claws and fangs at the ready. The water churns up around them as they collide, thousands of bubbles bursting forth with each tail slap and headbutt. Kiyoomi takes revenge for his shoulder wound by nearly biting one of Wakatoshi’s arms off. The great white shark momentarily retreats, his injured arm dangling uselessly by his side. He grimaces, but continues forward anyway. He can’t give up now.

Even with only one working arm, Wakatoshi is _fast._ He slides under Kiyoomi with one snap of his tail and rears up, attempting to finish what he started yesterday by tearing off Kiyoomi’s dorsal fin. But this time, the orca is faster and he twists nearly 180 degrees to avoid the deadly bite. He follows his momentum up with a sweeping slice that carves through the soft flesh of Wakatoshi’s exposed belly, releasing a cloud of blood into the water that makes Kiyoomi’s black eyes turn a bright crimson, his inner Alpha taking over at the first sign of weakness from his opponent.

It goes downhill from there. Wakatoshi gives as good as he’s got, the power of a great white shark singing through his veins with each nasty bite, but he’s still injured from the vicious treasure hunt fight and he’s only got one good arm. Meanwhile Kiyoomi is extra-aggressive, his wounds fixed with Omegan saliva, and he’s got both power and speed to spare. He also avoids bare-skin contact with Wakatoshi as much as possible because of the merman’s rough skin texture, which could shave away at his own skin if he isn’t careful.

Atsumu drinks it all in with greedy eyes. The heat in his belly is nigh unbearable, the fledgling Omega instinct within him going crazy over the Alpha pheromones in the water, begging for him to be mated soon, to trigger his true heat, to receive a bonding mark that will tie him to his Alpha, to be filled by his monster cock and knotted and fucked until he’s stuffed full of cum. He rubs the part of his tail around his slit, hoping that the ache will be relieved soon.

Things come to a head when Kiyoomi traps both of Wakatoshi’s arms behind him and pins him to the rocky platform. He clamps his jaws shut over the shark merman’s vulnerable trachea, holding on steadfast despite Wakatoshi’s wild thrashing, and jerks his head roughly to the side. Atsumu winces as the movement rips Wakatoshi’s head off of his shoulders, killing the merman. The headless body convulses, the heart frantically attempting to pump blood into a brain that’s no longer there.

Kiyoomi drops his competitor’s head from his teeth, bright red blood painting his face with the stuff of nightmares, and lets the body fall alongside it. He clenches his fists and faces upwards, letting loose a resounding victory scream that shakes the foundation of the platform and temporarily halts the other ongoing battles. The members of Kiyoomi’s tribe who are still around break into thunderous applause, hailing the strength of their leader’s youngest heir. The head of the Deep Ocean tribe shakes his head with a disappointed sigh, swimming forward to claim the body.

Atsumu knows what’s coming for him even before Kiyoomi’s head swivels towards him, his irises still as scarlet as the blood he just spilt. The lionfish lets loose a low crooning noise that he hadn’t even known he could make, opening his arms wide in invitation. Kiyoomi’s pupils blow wide and black with unadulterated lust.

In a flash, his hands are around Atsumu’s waist. Atsumu clings to him, wrapping his tail around Kiyoomi’s bulk and sliding his slit right up against the slick skin of the orca’s stomach, letting out a needy whimper. Kiyoomi growls, the vibrations resounding in his chest. He wraps his strong arms around Atsumu’s back and shoulders, propelling them away from the platform with quick, hard strokes of his tail. Atsumu doesn’t question how Kiyoomi knows where his cubby is; the heat in his belly is slowly consuming him with the need to mate with this Alpha right here, right now. He lets out another whine, louder this time, spurring Kiyoomi to swim faster.

Atsumu is all but thrown through the entrance of his cubby when they reach it. He flips over on his side to avoid crushing his delicate spines, and then Kiyoomi is on to him. They are both too far gone to attempt any conversation. Their base instincts as an Alpha and an Omega take over, all sense of rational thought locked away by the mindless need to mate. Atsumu reaches up and rubs his throat against his Alpha’s, first one side, then the other, triggering Kiyoomi’s rut.

The orca roughly fists Atsumu’s hair, yanking his head up to expose his neck. Despite seeing him literally rip someone’s head off earlier, Atsumu isn’t afraid. Even seeing Wakatoshi’s blood still staining Kiyoomi’s teeth doesn’t make him feel anything other than immense satisfaction that his rightful Alpha put another in his place. He croons again, baring his throat and letting his head flop to the side so that Kiyoomi has unrestricted access to his scent glands.

Kiyoomi doesn’t waste the opportunity. He mouths feverishly at Atsumu’s neck, not quite biting down, but licking over each gland repeatedly to induce the production of slick. Atsumu keens, rutting his slit up against Kiyoomi’s tail. He can feel the heat moving downwards from his belly, his slit peeling back slightly to expose both his small Omegan cock as well as the lips of his labia, which are slowly puffing up as he grows more and more aroused.

“Alpha,” he whines, pawing at the orca merman. “Please—”

His Alpha’s eyes flash red. Kiyoomi releases Atsumu’s hair and bends down so that he’s at eye level with the slit. Then he sticks his tongue directly into Atsumu’s cunt, lapping up the slick that gushes out as Atsumu jerks up with a wail. It feels so good, so warm and wet and sensitive. Atsumu’s cries grow louder as Kiyoomi eats him out, his hands gripping tightly on to Atsumu’s hips so that he can’t wriggle away.

Atsumu grabs the curly strands of Kiyoomi’s hair, tugging lightly to get his Alpha’s attention. Kiyoomi looks up at him through dark eyelashes, still licking deep into Atsumu’s insides. The lionfish shudders and squirms as his tongue presses into a particularly sensitive spot. Little bright lights flash behind his eyes as the pleasure runs through his veins like molten lava, creeping and hot and slow. He tugs Kiyoomi’s hair again, insistent.

The orca finally retracts his tongue, giving Atsumu a temporary reprieve. “What?” he rasps, his voice low and husky.

Atsumu beckons him to slide back up as he can whisper three words into Kiyoomi’s ear that he’d never ever thought he’d be saying with so much desire, “Omi… _breed me.”_

The next thing he knows, he’s flat on his back, staring up into the face of his Alpha as Kiyoomi ruts shamelessly against him, grunting as his own slit parts to reveal a hard, thick cock that’s as pale as his near-translucent skin, the tip flushed an angry red. His knot hangs heavily below it, thick as a fist and twice as arousing as it is intimidating.

Atsumu tries to relax his back muscles as much as possible to make his spines lose their stiffness, that way they won’t break while he’s getting his brains fucked out. His mouth waters at the sight of Kiyoomi’s cock, imagining that huge dick plowing deep inside him, and he lets out a needy moan.

“Alpha,” he pleads, rubbing his labia up against Kiyoomi’s dick. “I need ya, please, need ya inside me—”

Kiyoomi’s arms shoot out, his elbows digging into the rocky surface by Atsumu’s face. “You want my cock, baby?” he growls, teasing the leaking head against Atsumu’s hole. “Want me to fuck you so hard that you forget your own name?”

“Yes, yes, yes! Gimme yer cock, please!” Atsumu bleats, more slick leaking out of him in anticipation of what’s to come (literally).

“Fuck,” Kiyoomi breathes, nosing into Atsumu’s hair. “Look at you, you’re so pretty, my beautiful little Omega.” He thrusts into Atsumu with a single smooth stroke, both of them groaning in unison as Atsumu welcomes him deep into the heat. Atsumu’s mouth falls open as Kiyoomi breaches him, feeling a brief sting of pain from the initial intrusion race up his spine, but it’s gone just as quickly as it comes.

He keens loudly, holding on to Kiyoomi as tight as he can. The orca curses as Atsumu squeezes tightly around his cock, canting his hips to see how far Kiyoomi can reach inside of him.

“More!” Atsumu demands. “Make me yours, _Alpha!”_

And then he’s rendered effectively speechless as Kiyoomi pulls out and slams himself back in, setting a brutal pace that has Atsumu crying out little noises of pleasure. He feels a different sort of heat in his belly, one that winds up like a spring tighter and tighter as Kiyoomi fucks him into the floor of his cubby.

“Omi! S-so good, _hnngh,_ oh Neptune, I’m so full! Yer so b-big! _Ah—_ yes, more, please! _Omi!”_

A harsh breath, then, “Tell me how much you love my cock.”

Atsumu is quick to obey, “I love how big ya are, how full ya make me! Yer the only one I want, Omi!” He cries out as Kiyoomi gives him a particularly rough thrust, hitting his prostate with dead-on precision that makes him moan even louder. Every time Kiyoomi thrusts into him, his hard cock presses against all of Atsumu’s nerves, sending him spiraling into fits of pure happiness.

The orca swallows his moans by kissing him, nipping at his lips and tongue, pulling off to leave marks on his neck and torso, all the while continuing to piston his hips into Atsumu’s slick cunt. The pleasure between them builds and builds and builds, until one last thrust has Atsumu screaming his Alpha’s name as his first orgasm rips through him like a tidal wave. Kiyoomi snarls as his muscles contract, squeezing him tightly. His knot swells and he lets out a roar. He bites down hard on Atsumu’s scent gland at the same time he shoves his knot into his mate’s hole, sealing them together.

Atsumu feels a burst of white-hot pain-pleasure rush through him as the bonding mark takes a hold of him, triggering his true heat. His inner Omega coos in satisfaction as he feels Kiyoomi come inside of him, a hot gush of seed painting his insides. He moans, his senses filled with the smell of sex and safety and pure Alpha. Kiyoomi’s knot soothes a bit of that persistent ache inside his belly, but he knows that one round is not nearly enough to satisfy him.

Kiyoomi pulls back to lick at the bite apologetically, soothing the reddened edges of the newly-formed mating mark. Atsumu purrs, stroking his Alpha’s hair contentedly. They chase each other’s lips while they wait for Kiyoomi’s knot to go down.

And when it does, Kiyoomi is all too happy to perform an encore.

* * *

Atsumu’s first heat lasts for three days, during which he does absolutely nothing but get repeatedly dicked and knotted by his Alpha’s monster cock. Kiyoomi places a mating mark on his other scent gland, continually renewing both marks during the whole cycle. Neither of them eat, physical hunger being replaced by the frenzied desire to keep mating, and only sleep a bare handful of hours before they wake up and get back to fucking like rabbits.

On the fourth day, Atsumu wakes up with his mind no longer feeling muddled by lust and heat hormones. He smiles when he sees Kiyoomi sleeping next to him, his curls framing his pretty face and making him look softer than the sex-crazed beast from the past few days. Kiyoomi’s left arm is slung over his hip, his other arm bent above his head, and their tails are intimately intertwined, the flukes resting on top of each other. Kiyoomi’s cock is still sitting heavily inside of him from their last coupling, although it’s long gone soft and his knot has dwindled.

Atsumu wonders if he managed to get pregnant. With how much cum he had stuffed into him during those three days, he wouldn’t be surprised if he did.

Now that the haze of heat is over though, he’s starving. But he doesn’t feel like moving.

“Omi, Omi,” he whispers, nudging his mate. Kiyoomi’s brow scrunches up and he grumbles something unintelligible. “Omi, wake up. I’m hungry.”

Sleepy black eyes blink open. “Mmph,” Kiyoomi groans, stretching his arms. They both wince at the crack that his joints make. Atsume makes a hitched noise when Kiyoomi’s dick slips out of him and back into his slit, leaving him feeling bereft. The void of not having a giant cock stuffed inside of him all day and night makes him almost want to go at it again, but he’s also really hungry. And kind of sore, if he’s being honest. Being nailed for three days straight will do that to you.

“Omi, food. ‘M starvin’,” he whines, rubbing the tip of his nose against his mate’s scent glands.

Kiyoomi peels himself away from his mate, both of them pausing as the loss of contact echoes within them mournfully. “I’ll be right back,” he says, nuzzling against Atsumu, sliding their throats together to mix their scents together even more. Then he swims out of the cubby in search of bluefin tuna.

Atsumu languidly stretches out, pleased to find that the heat that’s been haunting him for over a week has vanished, replaced by the satisfying tingle of Kiyoomi’s marks upon his skin. He prods gently at his belly, but it’s still flat as the ocean floor despite all the cum that Kiyoomi had dumped into him. Well, it’s not like guppies are formed right away. Atsumu has grown up watching his tribe’s Omegas get steadily bigger week after week, until they’re ready to pop out their litter.

He spares a thought for how Osamu and Michinari are faring. He’ll see them once their tribe is finished with mating season and they’ll all go home together.

Atsumu pauses at that word, ‘home.’ He and Kiyoomi are from separate tribes. Either he will have to go with Kiyoomi to the Pacific Nomads or Kiyoomi will have to come back to the Inari Reef with him. He’ll have to speak with his mate about that when he returns. Atsumu has already made the decision in his heart to give up the Inari leadership to Osamu when it’s time for Tomoka to step down, so it’s not like he has a particular attachment to his colony. But when he thinks of his tribe, he thinks of his people who are waiting for him and Osamu to return home.

Especially Shinsuke. Atsumu’s eyes widen and he sits up with a gasp. Oh Neptune, _Shinsuke._ There’s no force on Earth that can prevent Atsumu from going back to see Shinsuke’s guppies. He’ll have to convince Kiyoomi to go back with him, at least so he can reunite with his senior Omega mentor and meet his and Aran’s children.

It doesn’t take long for Kiyoomi to return with an armful of fish. One large tuna for Atsumu and several smaller fish for himself. Atsumu drools when he’s presented with the tuna and he spends the next several minutes in bliss as he gobbles it down. Kiyoomi is so good to him, he really lucked out with his choice. He leans against his mate afterwards, snuffling sleepily against his chest.

Kiyoomi holds him close, licking over his skin to groom him and clean him up after all their mating. Atsumu closes his eyes and relaxes into the embrace. It feels really nice to be taken care of. Shinsuke was right, he had nothing to be afraid of.

He resurfaces from his happy daze when he recalls what he’d been thinking about earlier. He raises his head. “Omi Omi, I wanna talk t’ya ‘bout somethin’,” he says, putting a halt to Kiyoomi’s grooming. The orca gazes down at him questioningly, his eyes wide and round in his face. “Since we’re mates now, we gotta live with one of our tribes, right? If it’s not too much trouble, I wanna go home to the Inari Reef first, ‘cause one o’ my seniors was pregnant before we came here an’ I wanna meet his guppies before I leave ta be with yer tribe.”

Kiyoomi makes a startled noise. “You want to live with my tribe? We travel a lot, you know, being nomads and all that. We never stay in one place for long. You’d be fine with a life like that?” he asks.

“Well, not if I’m super pregnant,” Atsumu admits sheepishly, raising one hand to stroke his flat stomach. “It’s just… I’ve lived my whole life in one place an’ I wanna see what’s out there beyond the reef. This is the first I’ve ever gone anywhere outside an’ I wanna see _more._ An’ I wanna see everything with ya by my side.” He smiles when the orca lights up and presses little kisses to his face, over his brows and his nose and cheeks. “Hey, stop that, it tickles,” he laughs.

“You just said you wanted to spend the rest of your life with me, how can I not be happy?” Kiyoomi says, hugging Atsumu close so he can lick over the healing mating marks on both sides of Atsumu’s neck. He pulls away briefly so that he can bend over and nuzzle Atsumu’s stomach. “I hope our little ones will be happy, too.”

Atsumu blinks, his breath hitching. “Ya can tell if I’m pregnant?”

“Mmhm. I can smell the change in your scent.” Kiyoomi nudges at his abdomen with his nose. “Right here. You’re going to be the mother of our children, Atsumu—”

The lionfish tackles his mate to the floor of the cubby, kissing him enthusiastically. He did it, he’s pregnant! By the gods, had it really only been a little over a week ago that he’d been reluctant about mating and having his own guppies? Now Atsumu can’t think of a future without those things.

He can’t wait to tell Osamu.

* * *

When Atsumu and Kiyoomi leave the cubby to greet their respective tribe leaders, Osamu, Rintarou, Michinari, and Hitoshi are waiting for them. “Took ya long enough,” Osamu huffs, turning up his nose at the sight of Atsumu’s dopey, lovestruck grin as he hugs Kiyoomi’s arm.

Both Rintarou’s and Hitoshi’s noses twitch, nostrils flaring as they approach. A sly smirk crosses the eel merman’s thin face as he says, “Congratulations, you two.”

Osamu looks askew at him, confused. Then his eyes widen, and he whips back around to stare at his twin with shocked eyes. “Tsumu… are ya really—?”

Atsumu runs a hand over his stomach. “Yeah. I’m pregnant,” he confesses, his striped fins fluttering around him with glee.

“Wow, ya actually went an’ did it,” Michinari says, awed. “Congrats, Tsumu!” Atsumu turns pink, pleased and embarrassed all at once. He preens a bit, unable to help himself.

Tomoka swoops down from out of nowhere, cheshire grin on her face as she beholds the sight of her other son. “Ya sure have been busy, I see,” she says, giving a cordial nod to Atsumu’s new mate. She sniffs, her eyebrows flying up when she registers the difference in Atsumu’s natural scent. _“Really_ busy, since yer already pregnant. I swear ya were a guppy just yesterday and now yer goin’ and havin’ yer own babies. My lil Atsumu’s all grown up!”

“Mum!” Atsumu whines as everyone else breaks into laughter. A smile tugs at Kiyoomi’s lips.

“So are ya gonna come back with us or are ya gonna join yer mate’s tribe?” Tomoka asks.

Atsumu can see Osamu and Michinari straighten up at the question, casting unreadable glances in his direction. "Omi an' I were just talkin' 'bout that, actually. We're gonna go back to Inari Reef with ya so I can meet Shin-san's guppies an' say g'bye ta everybody, then he's gonna take me back to his tribe. Samu can be the next leader, I just wanna be free ta do what I want," he says, slightly apprehensive at the thought of living separately from his twin for the first time.

Tomoka shrugs. “Alright, can’t say I didn’t see that one comin’. Ya always were such a lil rascal back in the day.”

Atsumu blushes again. He turns even redder when Kiyoomi leans down and whispers to him, “You’re so cute, Atsumu.”

His brother and Rintarou mime gagging behind Tomoka’s back, while Michinari and Hitoshi simply look amused. Atsumu takes revenge by grabbing his mate’s face with both hands and planting a fat, exaggerated kiss on his lips that ends up turning into a real one when Kiyoomi enthusiastically returns the gesture, devouring the squeak that Atsumu makes when he’s tugged against his Alpha’s broad chest.

They only separate when Osamu yells in horror, “For the love of Neptune, get a fuckin’ room!”

Atsumu hides his face in his hands, cheeks feeling hotter than magma. His mate had just made out with him in front of his _mother._ He doesn’t think he can look her in the eyes ever again, no matter how hilarious she just finds this whole affair (and he can tell she thinks it’s entertaining by the sound of her unrestrained laughter).

“Can we please just leave now?” he groans, peeking through his fingers. Kiyoomi’s arm snakes around his waist, solid and warm. And, if he’s not mistaking it, a bit protective from the way his large palm comes to rest on the flat dip of his stomach.

“We’re still waitin’ on a couple o’ others, and then we’ll be good to go. Ya best go greet yer new tribe while they’re still around,” Tomoka says. She smirks at Kiyoomi. “I’m sure they’re dyin’ ta see ya after that stunt ya pulled killin’ Takashi’s eldest and then immediately disappearing with my son. My goodness, I haven’t seen an Alpha battle that bad in a few years!” Kiyoomi nods, looking a little sheepish at the mention of how violently he had behaved in the battle royale. He gently pulls Atsumu away from his family, head swiveling to locate where his father is in the basin.

They pass by Koutarou and Keiji, who are speaking quietly with the leader of the Deep Ocean tribe, Takashi. Atsumu feels Takashi’s gaze fall on him first, then Kiyoomi. “Congratulations, son of Tomoka, son of Katsutora,” he says, a wan smile on his aging face.

Kiyoomi inclines his head respectfully. “I apologize that I could not end my battle with your son on better terms.” Atsumu holds back a wince at the memory of Kiyoomi’s sharp teeth tearing through flesh and bone like they were nothing to him.

Takashi shakes his head ruefully. “Don’t be sorry, this is simply the way things are. Wakatoshi was a prideful boy, and it became his downfall. He could have backed down any time he realized that he was outclassed, but he did not. You earned the win fair and square, son of Katsutora. So once again, congratulations.”

“That was quite a show you put on back then!” Koutarou jumps in, beaming. “Reminds me of how hard I had to fight for Keiji three years ago!” He breaks out in a wide grin, pulling his mate close to him. “Prettiest Omega I ever saw, it’s no wonder you had the most suitors out of everyone else. But that didn’t stop me!”

Keiji chuckles, “That’s right. If anything, you were even more vicious than Kiyoomi, slaughtering your competition left and right so that they couldn’t look at me anymore.”

Atsumu can totally see that happening, considering how much of the kitefin shark Alpha is pure muscle. But as much as he’d love to stay and talk, he and Kiyoomi do actually have somewhere to be. He tugs at Kiyoomi’s arm and the orca looks down at him briefly. “We should get goin’,” he says. “Yer tribe’s waitin’, remember?” Kiyoomi makes a noise of assent.

“Oh, didn’t mean to keep you here! Go on then!” Koutarou says, making shooing motions at them.

“Excuse us.” Kiyoomi bows his head again before he and Atsumu take their leave. Atsumu sees Keiji give him a small smile, mouthing to him, _Congratulations on your pregnancy._ Atsumu's hand automatically goes to his stomach, wondering when he'll start to feel the first signs of life within it. He imagines what they may look like, these little lionfish-orca hybrids. Maybe they'll have Kiyoomi's wild curls, or Atsumu's pale-yellow hair. Maybe they'll have stripes, maybe they won't. Or a nice, even combination of them, guppies with Atsumu's venomous spines and an orca tail. Atsumu secretly hopes that they'll look more like Kiyoomi than him, because Kiyoomi is obviously the more gorgeous one of the two of them. Atsumu knows he's pretty, but Kiyoomi is _beautiful._

Oh, there he goes again, waxing poetic about his lovely Alpha. Kiyoomi gives him a confused glance as Atsumu plasters himself to his mate's side, hugging Kiyoomi's arm to his chest. Atsumu just grins at him and says, "Love ya, Omi." Kiyoomi turns bright red and looks away. Aw, he's embarrassed! Atsumu laughs, feeling a content warmth filling him up inside. He could get used to a life like this.

They find the Pacific Nomads tribe in the northeastern area of the Fukurodani Basin. As one they turn to greet them, dozens of curious eyes boring into Atsumu as if trying to see through his soul. He’s not afraid though, not with Kiyoomi’s hand clasped gently over his own. He gazes back at them, looking head-on at the faces that will become his new family.

“Kiyoomi,” rumbles Katsutora, looking every inch the proud father. “Well done on your big debut.” His tribe echoes the sentiment, some with whistles and wagging eyebrows that make Atsumu blush. Kiyoomi just rolls his eyes at his tribe’s antics.

“Thank you,” he responds. He smiles at the crowd, and Atsumu smiles with him. Together, they raise up their hands to their new tomorrow. “Everyone, I would like you to meet my beautiful new mate—Atsumu.”

**Author's Note:**

> sorry wakatoshi i have nothing against you, i promise, i just needed someone to compete w/ kiyoomi
> 
> Species list:  
> Atsumu & Osamu - lionfish  
> Shinsuke - striped beakfish/barred knifejaw  
> Aran - whale shark  
> Michinari - Banggai cardinalfish  
> Hitoshi - sand devil/Atlantic angelshark  
> Kiyoomi - killer whale/orca  
> Rintarou - moray eel  
> Shouyou - clownfish  
> Tobio - Caribbean reef shark  
> Koutarou - kitefin shark  
> Keiji - spinner shark  
> Wakatoshi - great white shark  
> Hitoka - butterfly fish  
> Kourai - goblin shark
> 
> Please leave a comment before you go~


End file.
